This is M VESA Desktopmount Dual Stand Expansion Kit. A heavy duty dual monitor expansion kit desk stand that is combined with the M VESA Desktopmount Dual Stand. This extends the M VESA Desktopmount Dual Stand (sold separately) to a 4 monitor installation.The table stand can also easily be exchanged to the M Desktopmount Desk Clamp (sold separately) to create even better space on your desk. For a thru-hole installation there is an M Desktopmount Single / Dual / Triple Stand Grommet Base available.