Product was not properly de-burred from cutting, especially the cylindrical tube part. I purchased a small and it fit perfectly. My water bottle bounces out onto the ground when my bike hits a bump. Battery life appears to be decent at about 2 solid days of constant use before it dies off. The pump it comes with is pretty good but get a Coleman rechargeable pump or something like that. Of these, the AudioTechnica (this phone) were the worst! Great sound quality and microphone also. I do put a lot of miles on my shoes. Fit perfectly, Im normally a size 8 & ordered an 8 so I wouldnt worry about sizing up or down. I replaced these with sturdier ones from my local HW store, and that did the trick.