The 2-1/2" Grip Head, KG200912 consists of a pair of rotating aluminum discs attached to a hexagonal stud designed for the Convi and Super Viser Clamp systems. The discs have four different sized "V" shaped jaws to accept any accessory with a 5/8", 1/2", 3/8", 1/4" mounting stud or tubing. The "V" shaped jaws have "teeth" that grab whatever is mounted between the plates securely. The KG200912 uses a non-slip aluminum friction disc that will maintain its durability over time that offers the user positive locking strength and precise control. The 2 1/2" Grip Head is most often used in conjunction with a grip arm, giving you complete flexibility to position gobos-- "go betweens"-- such as flags, scrims and silks as well as other accessories virtually anywhere. This grip head is clad in a stealthy black powder coated finish.