Product features: (the biggest characteristic bracket bottom four teeth screw holes) 1 the stamping precision mould good consistency easy to install 2 compatible with SSD solid state disk and hard disk 3 compatible with SATAI SATAII SATAIII 4 the hole and 3.5 inch hard disk position completely consistent as long as the hard disk can be placed in the position the shelf can be placed please see the bracket bottom plate with eight holes four holes in the middle are without teeth used for the installation of 2.5 inch disk on the edge of the four holes with teeth the position and 3.5 inch disc screw holes completely consistent! 5 2mm thick steel plate material no deformation heat quickly to maximize the protection of your hard disk