AUSTAR autoclavable cleanroom overboots is designed to drawstring, which can be easily adjust tightness. There is also a tie rope designed at the feet surface, so that the feet are fixed and do not move back and forth in the boots. Shoes - Autoclavable Cleanroom Overboots also called Cleanroom Autoclavable overboots,Cleanroom Shoe cover,Cleanroom Soft soled sock Product Specifications: Resistant to multiple times of steam sterilization Flat-insole design, wear directly after put on socks Ohter Information Size: S/M/L/XL Color:white(Other colors available per request.) Application grade: cleanroom grade B/C/D