The Quick-Link Receiver from Arca-Swiss is for the Quick-Link Tripod Head Quick Release system. It is useful for being able to quickly exchange tripod heads on a leg set when working with multiple types of tripod leg sets. The Quick-Link set makes it possible to travel light by carrying multiple leg sets or other head mounting options. Additionally, it features a 3/8"-16 threaded mounting socket, compatible with most tripod leg sets. The installed 2.8"-diameter receiver can be left permanently on the tripod.