(6) Gotoh nickel press-in tuner bushings for locking post(front locking) Magnum Lock tuners. These have a line on the knurling to denote 6mm inside diameter and only fit the locking post tuners...will NOT fit other gotoh standard keys that use 1/4" post or locking tuners with the knob on the rear of the housing. Outside diameter is 11/32"(8.75mm) and inside diameter is 6mm.