Material:Made by Airplane Aluminum which is strong and light weight. Surface: corrosion resistance, stand wear and tear,and surface smooth. Compatibility: This PU-70 quick release plate fit for not only Benro B/ J-series?Ballhead, but also other Arca Swiss compatible quick release systems ballhead such as Sirui, Photoclam, Markins, etc. Camera screw: Stainless steel camera screws, 30% larger than the standard screws, increasing?hardness and fastening strength of the Quick Release Plate. You can change the location of the screw to fit different cameras.