I didn't buy mine from Revain but it's the same product. At first I was very happy with them. I timed it and it took my tires about 4 minutes to depressurize to 10psi. I didn't want to spend $40 a tire on devices that deflate to a predetermined psi pressure. (Some assholes gave it 1 star for not turning itself off automatically.) I only void 1-2 times a year. My problem started 2 weeks ago. I keep them screwed together and in my tool box. I've probably used them about a dozen times and couldn't unscrew some of them by hand. I had to use pliers to disassemble it. Somehow the caterpillars got mixed up while being together and protected. That confuses me. It seems brass might be a better choice than soft aluminum. I would buy them again, the price is not clear. But now I dump 6-12 times a year and think the automatic will be worth the extra money.