Spring-loaded clamp that securely attaches to a pipe or plate up to 40 mm in diameter.

The Manfrotto 175 Spring Clamp is a spring-loaded clamp that can be attached to a pipe or plate with a maximum diameter of 40 mm using its powerful rubber-coated jaws. The clamp has a 16 mm clamping screw-lockable mounting hole for a spigot, for example, and a fixed half-spigot. There is a 3/8” female thread in the middle.
At the end of a studio stand, this acts as a holder for a backdrop or reflector, for example.