2 of 5 Won't bind valve stems. It pops out very easily rendering it unusable. I've been lucky enough to even get it to clamp on 4 out of 5 tries, but on the 5th try I have to somehow hold it in place and twist until I find the perfect spot for the 3 prongs to sort the clamp be able . on the valve stems. Once I think I've found the perfect spot, I slide the locking mechanism up and very slowly take my hands off it. If it only rotates 1/8 inch after I remove my hands, forget it, it will pop out.