The 3M Foam Non Adhesive Fenestrated Dressing is a fast wicking, non-swelling polyurethane foam with a highly breathable film backing. This backing prevents wound exudate strike-through. It also acts as a barrier to outside contamination. They are sold by the box of 10 each. Ref # 90604 3M is a leading manufacturer in wound care supplies. ADW Diabetes carries a wide range of wound care products at great discounts, each and every day! Please review the size, style, and quantity carefully before ordering. If you have any questions on this wound care product or any other products we carry from 3M, please call our customer care specialists toll free at 877-241-9002.