TLDR: You gotta be lucky if this works for you the way you want it. Im 411 and 102 lbs and bought the small. Perfect fit lasts they about 6 months with every day use, the cushion on the sole will begin to flatten, once this happens time to reorder. The glow in the dark part is amazing! (If I forgot and left it unplugged overnight, then I had to wait to recharge them). With the factory cord! Replacement item came damaged, the first item was missing parts screws and was not able to put together due to no locking bolts where screws go. Vale pelo preço e qualidade! Update: 10/6/20 Still my favorite bike accessory. In a bajillion colors.