A ventilated Ray Optics box which is open fronted with extended sides finned externally for heat dissipation and vertical internal grooves to accommodate a slit plate and cylindrical lens. The ray box includes:. 1 x 12V, 21W lamp with one meter of twin flex ending in 4mm connectors,. A single and triple slit, whitened on one side, black matt on the other. The ray box operates on a 12V power supply (B8G85458) which is not included. 45mm width: not suitable for use with 50mm filters. Replacement bulb is available to purchase separately (B8A56820).