I bought these because I had so much liked a pair of Rieker sandals that I bought locally. The sandals are also size 38 and fit perfectly; I wore them on a European trip.  However, this medium width Rieker slip on shoe is too wide for my feet and I have trouble keeping them on, despite the elastic gussets that are on either side of the tongue. So I can't recommend them for anyone with B width feet, but if you tend toward wide you'd probably really like them.  At the price, I'm disappointed.