This is an optional tripod mount for the Tamron 70-210mm f4 Di VC USD lens. It is compatible with Arca-Swiss style quick release plates and it allows for rapid attachment to a tripod. Featuring a hinge-type ring section, connection is easy even when the lens is mounted on a camera. To maximise the advantages of the lens, the tripod mount is made of lightweight, sturdy magnesium alloy.