precision quality Desmond brand 1/4"-20 Stainless Steel (metal) Tripod Screws. 1/4" metal male thread with both 4mm Hex (Allen socket) & coin slot. Shaft is 10.2mm in length, including the thread. Total length including base is 14.2mm. Head is 12mm in diameter (not inc D-ring). Head is 16.3mm in diameter at its widest point (inc D-ring).