This is a very affordable 3D printed adapter for mounting 30mm rod distance cage system components to 60mm or the other way around.
It comes with 4x M6x8 steel set screws for fixing the rod positions.
The adapter can be mounted on a optical table too using M6 threaded posts.
All DIY-Optics.com optomechanics are highly compatible with other industry standard optomechanics. (Thorlabs, Edmund Optics, Optosigma ..etc.)
See drawing for further dimensions.