These connectors are most commonly used to join 0.5mm telephone cable. As there is a moisture barrier gel inside the connectors, they can be used internally or externally. There are IDC contact blades for each wire, providing excellent connectivity for telephone and broadband. They are extremely easy to use. Just insert the wires that need to be spliced into each hole and press the button down into the lower case. The wires do not need to be stripped, as the blades will cut through the insulation and make contact with the copper conductor.
eBay