You dont even need the simple instructional drawing. Thought the size 13 also had a strap on the back but didn?t . This pair is much smaller in size and very thin. its just so much richer and warmer than other plastic buds ive used. It appears to be a lamination. Connects to my phone without issue. >>>IS THE BATTERY LIFE GOOD?Actually, I can?t answer that yet - I?ve been using them for a week so far and after charging them when I first got them, they?re showing absolutely no sign of needing charged yet. As a mom, I love these shoes and so does my son. I cant sew it because the lining on the inside of the slipper is still in tact. I expect these to last for many more years before I have to get them resoled.