I have promised me a better quality of these caps. This material is too hard and does not fit on to the screw (F-connectors). The nuts on the F-type connectors can not allow the caps are coated there are far too narrow. If these parts of a soft silicone were they could also seal. I'll throw these parts in the trash because they do not fulfill their purpose. I can only empfelen self to use waterproof sealing tape. 0 stars