Smith & Nephew Inc Opsite™ Post-Op Dressing with Absorbent Pad 4-3/4" x 4", Waterproof, Latex-Free Smith & Nephew Opsite Post-Op Transparent Waterproof Dressing with Absorbent Pad is a revolutionary post-operative dressing combining a high Moisture Vapor Transmission Rate (MVTR) film and the cushioning and absorbency of a low adherent pad together with an easy application carrier system. The hydrophilic polyurethane film on this dressing has Reactic properties that Switch On in the presence of moisture allowing any excess to transpire into the atmosphere.