This is a solid brass rear binding post extender. It eliminates the trouble of offset binding posts causing clipcord imbalance. This extender gives you an extra 7/16 1/2 inch. All threads are 8-32 american standard Dimensions are as follows: BASE PORTION .645 total length, .310 diameter at center, .370 diameter at base, .325 from base to center of screw hole EXTENDER POST .730 total length, .280 overall diameter