This is a solid brass binding post set nickel plated with an ultra conductive copper contact screw. All threads are 8-32 american standard and the contact screw is held in by a nylon tipped set screw. Dimensions are as follows: TOP BINDING POST .645 total length, .310 diameter at center, .370 diameter at base, .325 from base to center of contact screw BOTTOM BINDING POST .480 total length, .310 overall diameter, .300 from base to center of clipcord hole