These mounting hubs are awesome for mounting to practically anything to gain a strong connection (4 M5 Screws) to a set screw locking shaft hub. Since the spacing between the holes is at 20mm (standard spacing for V-Slot tracks) this opens a whole new level of mounting that will allow for configurations like never before! Check the pictures (there are lot’s of them) to see a few examples and download the model to see how you can incorporate this unique locking hub in your next build. Aluminum Black Anodized L-21 x W-21x H-6 4 Tapped M5 Mounting Holes 2 M3 Set Screws (included) Download Open Source Model Unsure if this product is compatible with our aluminium extrusions? Look for the Maker Store Compatibility Badges!