Review on CALPALMY AR-PRO 28 700x20-25C Road Bike Replacement Inner Tubes Presta Valve 42mm for 700c x 20, 23, 25 Tires (6 Inner Tubes + 2 Tire Levers) by Shane Tomko

So far I've used 3 pipes out of 6 and tested the other 3. The first had a leak at the base of the stem where it attaches to the tube itself - from my vision, beyond repair. The second tube worked as it should - no problem. Because of the problem with the original tube, I decided to test the rest. 3 of the remaining 4 tubes are in good condition with no leaks. the other has a leak along the pipe seam. now it can be reliably repaired; and was. but I didn't buy these tubes with the idea of repairing them. won't buy them again --- 1/3 failure rate is not acceptable.