Grover Titan Electric Bass Machines 145BC Guitar Self aligning thrust bearings with special butterfly buttons. Durable cast housing. End thrust bearings. Worm meshes perfectly with gear. Safety-type string posts with cutaway shoulders to provide slip-over. Two screws in housing apron provide greater holding power. May be used with ALL modern bass guitar headpieces. Screws and bushings included Color: Black Chrome; 2x2 (2 per side) Grover Part Number: 145BC