OPENBEAM is an amazing new aluminum extrusion design that gets rid of the expensive T-nuts used on other extrusions types.It replaces the expensive T-Nuts with M3 sized nuts and bolts that are available form most hardware stores at an fraction of the T-Nut's cost.This joint is good for extending small off cuts of Openbeam. It has 4 screw holes per side and has internal grooves that slot on all 4 sides of the Openbean extrusion.This joint can also be modified into a 3 or 4 joint component.Protoneer Blog - http://blog.protoneer.co.nz Protoneer Shop - http://shop.protoneer.co.nz