The first thing to mention is the tubes I received were manufactured by Kenda, see the photo.The second thing to mention is that buying tubes seems to be a crap shoot. Aside from whether or not you will get the correct tube when you order online (size, sealant, presta or schrader)...will the tube last?Lastly, when buying tubes...You can put a Presta into a Schrader rim all you need is an adapter to use a standard pump or compressor for air. You should also look into a lock ring to secure the valve into the larger Schrader rim hole. If you have an old bike, you may have to do this as some tire sizes that have Schraders are becoming harder to find tubes for.Buy Rim Strips or Rim Tape. Years back tubes came with rim strips, now they don't. Neither these nor the Slime tubes I purchased included rim strips.With that being said, below is my experience with these tubes....As some reviews mentioned tubes blowing up shortly after install, I inflated mine to see if there were any bulges or leaks.As the picture shows, I screwed up inflating my first tube. My air chuck stuck in the valve and by the time I got it out, the tube had stretched way beyond 26", was over 3 inches in diameter and turned itself inside out. Luckily for me, it did not blow or create a weak spot. I let air out of the over inflated tube, lightly inflated the second tube and let them sit for a few hours to see if they leaked, or any weak spots (bulges) appeared. Despite my over inflating the one tube, there were no issues. So I mounted them up.Once mounted, I brought them up to 50lbs and took a test ride. I weigh around 230 and there were no tube issues. Despite the bike sitting in the sun during a heat wave in the Northeast where we've had 100 plus heat indexes for about a week straight, there were no tube issues and the bike was lightly ridden.A month later, I upgraded my tires to Specialized Hemispheres with Flack Jacket and did some more light riding. About two weeks later, my rear tire began losing air and was going flat within three days.At first, I figured that all the negative reviews about these tubes must be correct. The only thing was that I had no issues at all with the front tube. There had also been no issues with the rear tube until the tire swap.Because the leak was so slow, my first thought was maybe the valve core had come loose. So, I decided to loosen it slightly and tighten it back up. This was the start of a learning curve.When I loosened the valve core, I was greeted with a few drops of light green liquid that immediately became tacky. Even though I hadn't ordered sealant filled tubes and there was no marking on the box or colored valve covers, apparently I had received at least one sealant filled tube.I tightened the core, aired the tire up and waited to see what would happen. The tire lost air again and I was baffled at how a tube, with sealant (that seemed to be active), could have such a slow leak. But, before I dug into the rear tire, I ordered in a pair of Extra Strong Slime Tubes as replacements.Upon removing the rear tube from the rim and tire, the mystery continued. There was no sign of sealant anywhere on the tube, rim or inside of the tire. When I put the tube in water, there were no escaping air bubbles. I dried the tube off and was taking one last look and as I was slowly turning the tube in my hands, I felt something hard and sharp on my finger. I couldn't see it, but could feel it. Turns out I found two more of these objects in different places. They were so small, they rubbed out of the tube with my finger and the one I caught a glimpse of was just a small dark dot on my fingertip.The Specialized tires had been ordered in and maybe something had gotten into the tire I put on the rear during shipping. The only other thing I could think of is the tires I removed had been ridden in Arizona and maybe some thorn tips were inside of those tires and worked their way in the tube before the tires were switched. Aside from that, there was absolutely nothing that where the bike had been ridden that would penetrate the tire tread and leave such a small object in the tube.Once the hard objects were removed from the Bell tube, the sealant flowed out of the pinholes and seemed to seal the punctures.So, at this point, do I throw the Bell tubes out and put the Slime tubes in? No.The Bell tube feels heavier than the Slime tube and reminded me of bicycle tubes that I had as a kid in the late 70's and early 80's that never seemed to loose air. Also, the sealant seemed to have worked exactly as it should have when there was a puncture (multiple ones in this case). Lastly, the front tube hadn't needed air since the Hemisphere's were installed.So, I put the Bell back in the rear tire to see how it does. Ironically, it's also the tube I over inflated.So far it's been three weeks of light riding and the tube has not lost air, nor has the front tube lost air since the tire swap.While my experience with the Bell has been a little frustrating, it's not by any fault of the tube. The tube survived being over inflated outside of a tire and rim and sealed itself after three small punctures. As of now it's 4 stars. If they continue to hold up I'll be giving them 5.Update......Unfortunately the rear tube began loosing air again and I wasn't going to chase the pinholes down and try to patch them. So I installed the Slime tubes in both tires.Tubes seem to be a crap shoot these days.One of the Slime tubes failed due to a weak spot.So the bike now has one Slime Tube in the front, and the Bell tube that I removed from the front on the back (where the Slime tube that failed had been).***Second Update******Ironically weeks after I wrote the above... The second Slime tube failed the same way the first one did.Meanwhile, the Bell is still doing fine in the rear wheel., where the first Slime tube failed.With the above being said, I will not purchase the Slime tubes again, but would purchase these Bell tubes again.For now, I'm going to install two new Schwalbe's and see how they perform and keep the Bell as a back up.***Hope some/any of this helps and good luck.Ordered two Bell bike tubes for my old Trek bike. One I received sealed in a box. It went on easily and inflated as expected. Perfect! I'm very happy with the Bell tube I received, that's why I gave five stars.The other tube I received appeared to be a return? Seriously?! It was an Acimut (not Bell) tube in a bag without a stem cap. I used a hand pump to test it out and it has a hole in it!I'm upset I received a 'used' tube of a different brand. You wouldn't choose to buy a tube in a bag without a stem cap at the brick-and-mortar store, so please don't send one to me in the mail. This one is going back.I have two trek bikes. Always have flats within a few miles. I added a 2nd rim band and still gotten flats using the green slim tubes.These I have already travel over 40 plus miles and no flats. (Double the travel I have been getting) still riding. The punchers always been on the rim side of the tube.I think owning two trek’s bike and both have the same. I don’t recommend buying a trek bike as it not any better than my china made bike. Sorry trek but that you put POS rims on your bike but other than that it is a good bike.They are durable and hold the air. Have been using Bell tubes for over 15 yrs and can't complain in all that time. They will last for years and hold air for a good 3-4 weeks or so before needing to be topped off again. Just make sure you use really good rim tape before you install them and then forget them. Of course run over something that punctures the tire and they will pop but that is a given. I have only used the standard version of these tubes so I can't attest to how well the self sealers work.The replacement set of tubes I bought for my bob duallie didn’t have the correct front tire size tube so I had to purchase it separately. This was easy to replace, I inflated it and have been on my way adventuring with my kids. Just with my kids the stroller probably has 70+ lbs in it and then add my soft cooler I throw on the front and my diaper bags, the stroller carries a ton of weight. We’ve been out on hot days with no issues, holding air great.Bike tire tubes, durable and can handle some yanking and pulling as you try to get your tire and rim situated. Ran a 10 mile break in test and everything was perfect.Hold 3 cans per tube and won’t burst when you tie it around your waist.Got to replace a flat tire (about 10 years old). Fits well. The tube felt heavier than the original ones. I hope that means the gel inside will help prevent leaks as designed.I have two of these for my daughters hybrid bicycle. The connection between the priesta valve and the tube is sloppy and doesn’t allow the bicycle tire to seat correctly in the rim and causes it to go flat after several rides. I thought I just had a defective tube and ordered a second one which had the same problem.I used ride bikes competitively and have changed a significant number of bike tubes. It’s not uncommon for the manfacuring on inner tubes to be sloppy but with two tires in a row, it leads me to believe this product is junk. I would not recommend these tubes.The tube is package in a shrink wrapped inside the box, see 1st picture. It's an original Bell tube. It felt like good quality rubber. Great value in my opinion.As for the size, it's your responsibility to order the right one. Just look at the size on the side of your tire. Mine was a 26" x 1.95", see 2nd picture.26" : This is the diameter of the tire1.95": That's the width of the tireI order the Bell tube that fits tire width from 1.75" to 2.25". I read some review where people complained about the size but if you order the wrong tube it won't fit or will be to stretchy.So far holds the air and works great. At that price, I do recommend the purchase.I don't know about the quality of the tube as I haven't ridden on this yet... However, the valve length was way too short for my hybrid-road bike. I think this is like the standard size. Just buy Continental branded tubes instead, because their tubes for road racing actually work great - and the valve length is increased as well. I won't bother returning this since it's not going to be convenient repackaging... ima just leave this useless tube in the storage.All in all, the valve was too small to fit my hybrid-road bike; it might be too small to fit yours too (installation/pumping)!I should have read the review first for this one, I though a tube would be a tube.I bought 4 of them and I got the same issue, they go flat within 10km, already broke two in two rides...The connection between the priesta valve and the tube is sloppy and doesn’t allow the bicycle tire to seat correctly in the rim and causes it to go flat after several rides. I thought I just had a defective tube and ordered a second one which had the same problem.Very frustrating product. The valve stem is way too short, shorter than any other tube I've ever used. This will not be usable with one of the more common 'autohead' pumps; you'll need a specialized presta pump. Furthermore there is some reinforcing in the tube around where the stem meets the tube. This is wider than 25 mm, so that the tube will not sit in the trough in the wheel. This causes the bead of the tire to pop up when you pump it up (see circled in orange). I spent an hour fiddling with this tube and was not able to make it work in my 700x28 wheel.