Don't buy them. I have used them 4 times. The first 3 times, perfect as advertised. My wife used it once herself - no problem. Thought I found the perfect chins. The 4th time they both lost and I lost over $400. never felt like they were falling off. If you find them on the side of the road near Lake Tahoe please let me know. For the money it shouldn't be. This sucks and I feel ripped off. Do not take any risks.