I've used it 6 times and all I can say is WHY I DIDN'T BUY IT BEFORE. Tire pressure drops so fast it's crazy. It pulls the valve stem out and lets air through quickly, then closes the whole thing by screwing the valve stem back in. It takes me 6 minutes to deflate all four of my 35" off-road tires from 35psi to 12psi for beach riding. YES 6 minutes. It took 15-20 each bit. I can't live without ARB's. There are cheaper options but beware, I have friends with them and they don't work. Spend more and get what you pay for.