This is a pillar/extension column with 10mm threads at either end to fit Vixen GP mounts or Synta clones such as Celestron CG-5, Meade LXD-75, etc.
Can also be used as an extension for Porta mounts, GSO Skyview, etc.
Height is around 25cm (10"). Not sure of weight as I don't have any scales handy. It's not super heavy but is well built. In my opinion this is better than the much longer and heavier Skywatcher HEQ5 extension column.
Asking $120.
Pickup available from Ryde in Sydney or can post at cost.