Socket features white ceramic body, tinned contacts, has center post for grounding, top mounts through a .865" hole in the chassis, 1&1/8" screw mounting centers. Socket fits 12AX7, 12AT7, 12AU7, 6247, 12DW7, 6EU7 and similar based tubes. Shield is spring loaded twist on bayonet type. As found on many new guitar amps. Brand New. Set of six sockets with shields.