Shaxon"s Category 3 Keystone style RJ12 female to RJ12 female feed through coupler is an ideal way to join two Category 3 RJ12 patch cables or flat satin telephone patch cables. Category 3 Keystone style feed through couplers snap into a wall plate, surface mount box or keystone patch panel to provide a junction point for backbone/horizontal network wiring pre-terminated with RJ12 modular plugs. Keystone style jacks are designed to snap into any standard keystone port with no tools required. This product features a Lifetime warranty.