Dust Cap + Lanyard for Ruggedized In-line Receptacle, Anodized AluminumProduct Datasheet Lose or forget the dust cap for your Ruggedized RJ45 Jam Nut, Flange Mount or In line receptacle? Find replacement dust caps here. Even though the receptacles are transversely sealed, it is wise to utilize a dust cap to keep contaminants such as dust, dirt and water out of the exposed contacts of the RJ5 receptacle. Features Anodized aluminum material Designed to work with L com's ECRP & ECSP line of ruggedized in line receptacles