Manfrotto 175F-1 Spring Clamp with 492 & cold shoe
This is a Manfrotto 175F Justin Spring Clamp which clamps onto pipes up to 1.6" in diameter, or stands or arms that have a 5/8 in top, or 3/8 in thread. The 0.7 lb clamp also features a cold flash swivel shoe for attaching a shoe-mount flash.