Hollow Conical Washer Plugs are made of silicone and suitable for use on holes with screw sizes ranging from M8 to M33. They are made with a tapered profile and a large flange. Hollow Conical Washer Plugs are hollow,  making them flexible to handle. They can be installed securely and removed easily with a grip flap at the end. The grip flap is useful for frequent insertion and removal.