This is a tall plastic humbucker ring with an arched bottom, designed for usage on arched or carved top guitars. This mounting ring is not an exact Gibson spec replacement ring. It has slightly larger exterior dimensions and mounting hole locations.
Height on side facing the bridge = 11/32 in. (8.84mm)
Height on the side facing the neck = 5/16in. (7.92mm)
Radius of arch = 16 in.
Pickup Mounting Screw Ctr to Ctr = 3 5/64 in. (78.25mm)
Ring Mtg Screw Loc. = 3 5/16 in. (84mm)L X 1 29/64 in. (36.89mm)W
Interior Cutout size = 2 49/64 in. (70.16mm) L X 1 17/32 in. (38.8mm) W
Exterior Ring Dimensions = 3 39/64 in. (91.9mm) L X 1 51/64 in. (45.87mm) W