Kangnice Stainless Steel Multi Spanner Wrench Knob Jack Tuner Bushing for Guitar Bass This pocket-size toothed wench will tighten or loosen most nuts or thumb wheels found on guitars, like output jack, control pot, pickup switch, tuning machine and bridge thumbwheels. All edges and surfaces have been chamfered and polished to avoid damage to body and surrounding areas. Made of 1.90mm (0.75) stainless steel. Size:9.3*2.7cm. Quantity:1Pc( Not include the guitar).