7 x 7 inch 1/4 inch thick 6061 T6 aircraft aluminum with smooth machined and chamfered edges. Type III matte black hard-anodized surface for added durability and glare reduction. Five 3/8"-16 threaded holes, the film & still industry standard for large ball heads, magic arms and other grip equipment and fixtures. Platforms are designed with 5/16" countersunk through holes for spiking them to the ground or affixing them to wooden surfaces. Each has a carry hole (small 7" OX Mini Pro Platform) for ease of toting or clipping to a belt or bag. (Not recommended leaving gear mounted on small plate when carrying). Platform bottoms are padded with non-slip 3/32" closed cell foam that enhances stability on rocky surfaces and protects delicate flooring such NBA basketball courts. Includes with every plate 1 - 3/16" allen key for 3/8" threaded stud 2 - 3/8" NC 16 x 5/8" long threaded stud 2 - 3/8" NC 16 x 3/4" long threaded stud *ballhead not included