The Clamp, with a male 1/4-20 stud, opens up to 1.5" [3.8cm] to mount your Zylight to car windows, tables, motorcycles, light stands, tripod legs, pipes, etc.
The Universal Joint, with female 1/4-20 on one end and male 1/4-20 on the other, uses hard rubber balls and studded sockets for very secure positioning.