This platform was purposely developed and built for the roll-o-matic model turntable. It is a laminated MDF-plywood-cork structure filled with sand.
The platform rests on four rubber spikes, down-pointed, which decouple it from the stand/table beneath.
Laminated structure covered by cork and filled with sand helps to dump vibrations coming from the turntable mounted on the platform.
This type of platform could improve the sound of almost any turntable, effectively isolating it from the vibrations coming from the rest of the audio system and/or the stand/shelf beneath, and damping vibrations coming from the turntable itself.