Review on SCK 2 Pack 20 Inch MTB Bike Tubes with Tire Levers - Schrader Valve, 20x1.75/1.95/2.10/2.125 Inner Tubes in Black by Nathan Hutchinson

Kit contains 2 bike tubes. I didn't check the tubes, I thought they are all the same and will work. After spending 10 minutes replacing this product with our broken tube, I was unable to get air in when trying to inflate the tires. I checked the pin and found that it is countersunk. This was enough to prevent a proper connection to the bike pump and thus prevent air from getting in. The second bottle was ok so I got 1 broken and 1 ok. I have asked amzn for a replacement so hopefully next time I ship I will have 2 working tubes instead of 1.