Cable Matters (5-Pack) Gold-Plated 3.5mm TRS Keystone Jack Inserts in White 3.5mm KEYSTONE INSERT joins two cables with 3.5mm TRS plugs; Connect cables for a headphone, microphone, IR repeater, MP3 player and more; Fits a standard opening in a wall plate for keystone jacks 3.5mm AUX COUPLER with female ports on both sides connects to a 3.5mm cable concealed behind the wall STURDY SNAP-IN CONSTRUCTION of 3.5mm feed-through keystone provides a secure connection; Re-usable keystone jack inserts can be easily disconnected and relocated when upgrading or redecorating TIDY INSTALLATION of 3.5 female to female keystone insert provides a professional looking installation in the home or office COST-EFFECTIVE 5-PACK provides enough inserts to serve your home theater system