I like products that are well made and don't cause me any problems. I tend to buy big brands or pay extra for premium products, so I've been very wary of buying an industry standard instead (amaze) that's over three times the price. I took the risk and so far I think it was worth the risk. I haven't owned them for a long time, so I can't comment on durability or functionality. I only bought it for a tire deflator and for that I give 5 stars, the gauge is cheap but read the same pressure as my good gauge so at least it works. Follow the instructions and advice from the seller and other reviewers. I did and was able to get the deflators to consistently bleed the air to 1psi. It took several attempts and adjustments. You are a bit slow. Initially, they are fast, but as the pressure approaches the set value, they slow down significantly. It takes about 15 minutes to raise my 35 x 12.50 x 17 from 36psi to 18psi. About half of that time is in the last few psi, so you get the picture. I usually put them on while I'm doing other chores and it's nice not to worry about over inflating, but when I'm in a hurry I put the deflators on and then go to each tire with my quick deflator, which shortens the time.