It uses USB type C To USB type A for windows and macbased pcs. We have an 18? center console boat that we take to the beach and anchor bow out. I normally use M but I found M is too big and S is too small. Also to add the quality of pads, however good, Ive seen difference in build between left and right pad. We ordered two to stagger beside one another. It is noticably different when I switch between these and my dress shoes. Youll fully tighten the left side and remember to replace the bottom side of the stay and the rubber foot now. I thought I might order a size up, but after having to pay to return them, I decided to buy a different shoe all together. These are my new favourite shoes, super light and comfortable, they are very well made and a joy to slip my feet into. I really like them