Algidex Ag I.V. PATCH Silver Alginate Catheter Foam Dressing, 1″ Disc with 4mm Opening. Provides quick and sustained antimicrobial barrier against a broad spectrum of wound pathogens associated with catheter related infections. Absorbs moisture around the catheter insertion site. Sterile patch of polyurethane foam coated with an ionic silver alginate and maltodextrin matrix. Up to seven days wear time. Does NOT require activation.