Freely positionable railing bar for the PR-Truss system. The bar can be inserted into the rail from the side and secured with a thumb screw. It enables flexible luminaires placement inside PreRig Truss when used with the optional PreRig Railing System. The unit requires the PreRig Railing System to operate. For shipment, packaging dimensions are 400 x 210 x 170 mm with a weight of 2.20 kg and a packing unit of 2.