OpenBuilds Three Way Cube Corner Connector (V-Slot)

From the shop's description

Corner Cubes V-Slot Corner Connector – Three Way Cube – Milled from Solid Aluminum – Black Anodized – Use as 3 way Corner Connector and/or Adjustable Wheel Block – Fits on 20mm V-Slot or T-Slot Profile Extrusion Systems Use with M5 x 8mm Low Profile Screws or 8mm button head screws