I wore these slightly oversized shoes for a few days and then stored them. Thickness is about 5mm. Disinfected. Please refrain from purchasing if you are concerned about used items. I will lightly fold them and ship via Yu-Packet Post Mini. Blue insole with a double structure. Insole - Color: Blue - Material: Rubber and fabric (back side) - Design: Double structure (blue and black) Thank you for looking.