These Shoe Covers have a Non-skid coating on a polyethylene blend laminated to polypropylene substrate. Sewn with no seam on bottom and elastic opening. The large size is 19x38 cm and the XL size is 19x51 cm. Sold by the case only. Large=shoe size up to 13 and boot size up to 10. XL=shoe size 14 and up and boot size 10 and up.