Musiclily 1/4 Inch Metal Stereo Guitar Bass Barrel Input Jack Mono Ouput Plug Sockets, Chrome Ideal for electric guitar and bass Hole diameter: 1/4" (6.35mm); Thread diameter: 11.8mm (7/16 inch) ;Length without poles: 38mm(1 -1/2 inch); Total length including poles: 48mm (1- 7/8 inch) Can be wired mono or stereoShort post is hot, medium post is for battery, and larger outermost post is for ground Made by metal alloy, with nut and washer Package Including:1 pc guitar Jack