Duoderm Signal Dressing DuoDERM Signal dressing is an adhesive, tapered edge, modern hydrocolloid wound dressing with a change indicator. It incorporates a unique ConvaTec hydrocolloid formulation that distinguishes it from other hydrocolloid dressings. The adhesive hydrocolloid matrix and the outer film on DuoDERM Signal dressing are permeable to moisture vapour and provide an occlusive barrier against bacteria, viruses, dirt and water. DuoDERM Signal dressing is indicated for use on dermal ulcers including full-thickness wounds, pressure ulcers (II-IV), leg ulcers, superficial wounds, partial thickness burns and donor sites.