Solid queensland maple knobs with metal insert and locking side setscrew, 3/4" tall x 3/4" diameter and 6mm or 1/4" internal diameter.
Upper knob for stacked concentric set with side setscrew 1/2" tall x 5/8" diameter with 6mm i.d.
Lower ring for stacked concentric set with side setscrew, 1/2" tall x 7/8" diameter with 8mm i.d.
Knobs have a 1/8" deep x 5/8" diameter countersunk skirt to hide the nut and washer.
