This 3/8"-16 Bullet Screw from Desmond is a 21mm-long screw designed with a small head to fit countersunk screw holes in select clamps. It is made of stainless steel for superior strength and corrosion resistance and has a 11.6mm-diameter head with a 4mm hex socket. The shaft is 21mm in length, and the 3/8"-16 male-threaded portion of this screw is 9mm long. It fits all Sunwayfoto and Desmond clamps (except model #DAC-38) and can also be used for many other brands and applications.