Base Size: The QR plate base size is 44mm x 44mm square, the conical square base installed in the tripod has a size of 1 3/4 "(44mm) in both directions. Compatible models: Suitable for Velbon CX-444 CX-888, CX-460, CX-460mini, CX-470, CX-570, CX-690, DF-50, Sony VCT-D580RM, VCT-D680RM, VC T-R640, Amazon Basics 60 inch silver tripod, as well as certain models such as Ambico, Ravelli, Sunpak, Opteka, Dynex, Polaroid etc. Quick installation: The QB-4W tripod mount attachment baseplate is easy to install and can quickly and easily connect the camera or phone tripod adapter to a compatible tripod head. Easy to use: The additional quick release plate makes it convenient for you to replace multiple cameras or devices using the same tripod at the same time, while also facilitating replacement and disassembly. Package content: You will receive 2 pack 44mm tripod quick release plate. Please note that this is the base installed in the tripod head opening installation. Please measure the opening size of the tripod head at two angles before purchasing.