It achieves nothing. Shaft length 18.25mm, shaft width 2.4mm. Head Width 6.75mm. Overall length 20mm. Regards, Les & Pat at Guitars Electric. For example;.
Set of 6 Guitar Pickup Height Adjustment Rubber Spacer Tubing
Musiclily Ultra Gold 2.5mm Stainless Steel Countersunk Pickup Ring Screws Set
Musiclily Ultra Black 2.5mm Stainless Steel Countersunk Pickup Ring Screws Set
Allparts GS-0064 Countersunk Pickup Mounting Screws - Stainless Steel, Pack of 8
Epiphone P90 Dogear pickup height adjusting shim/spacer
Roswell P90 Dogear pickup height adjusting shim/spacer
