We lost ours on a 6 hr drive to the beach. The F1s do not have that issue. The ugly is that I found this mice to be too small and not tall enough for even a medium-sized palm. This was easy to set up. Also the seller has free shipping and free returns Other sellers do not offer that another reason I bought from here! If you conceal carry and your firearms slide or your IWB holster stick to your skin? This is a great shirt to use to get rid of the issue. Very comfortable, feel like they will last well. I typically wear a 9 or 9. Very disappointed looks like I wasted my money, thought they were going to be good after the reviews I read. I ordered another Sanuk style and will wait to make a decision until I get them as they come in half sizes.