The freewheel body needs to be compatible with both the freewheel mecanism of your wheel and the cassette that matches your bike's drivetrain.
You'll find here all the freewheel bodies to cover our diverse types of freewheel mechanism (ID360, ITS4, FTS-L) and the numerous cassette standards (Shimano HG, XD, XD-R, Micro spline, Campagnolo ED, N3W, Single speed).