Mepilex Ag 4″ x 5″Antimicrobial Foam Dressing, Silver, Sterile. Safetac technology layer reduces pain and trauma during dressing change, does not adhere to the moist wound bed but to dry skin only, seals the wound margins and reduces risk of maceration. Polyurethane backing film breathable, moisture proof, bacteria and viral barrier. Antimicrobial activity within 30 minutes and sustained effect for up to seven days.