Cable Matters (5-Pack) Gold-Plated BNC Keystone Jack Inserts in White BNC KEYSTONE INSERT joins cables with a BNC connector; Connect equipment with BNC ports for CCTV security or high end video applications; Fits a standard opening in a wall plate or patch panel for keystone jacks BNC COUPLER with female ports on both sides connects to a BNC cable concealed behind the wall; Re-usable keystone jack inserts can be easily disconnected and relocated when upgrading; Gold-plated BNC connectors provide a reliable connection STURDY SNAP-IN CONSTRUCTION of feed-through BNC keystone provides a secure connection; Twist-on connect feature provides easy termination TIDY INSTALLATION of BNC female to female keystone insert provides a professional looking installation in the home or office; Recessed connector in the rear of the keystone jack provides more room to connect a cable behind the wall COST-EFFECTIVE 5-PACK provides enough inserts to connect multiple monitors to a security system