This drilling jig eliminates the time-consuming layout work usually associated with installing shelf supports. Rather than mark the location of every hole before drilling, you set the jig's rails at the desired inset from the edge, fix them in position with the thumbscrews on the clamp rods, and then drill. The jig guarantees that the holes will be exactly opposite each other and at equally spaced intervals. Twin-register pins positioned in the rails fit into holes you have already drilled, ensuring that the holes will continue to be accurately spaced. An entire upright can be accurately chain drilled with no chance of error and no need for detailed measuring. The register pins have tapered tips and fit snugly into any hole from 5mm to 10mm (3/16" to 3/8"). The 610mm(24") long rails each have 20 holes drilled at 1" intervals. Ample space for chip clearance is provided to allow for easy withdrawal of your bit and to prevent jamming or burning. The bush carrier registers perfectly in each hole and is easily moved along the rails. You are assured of holes drilled at exactly 90° because the hardened bushings are 20mm(13/16") long (substantially longer than others available). Ten hole sizes can be drilled with the bushings that come as standard equipment, a soft (unhardened) bushing (you drill to size) for custom application is also included. The jig comes with regular-length clamp rods for use with material 300mm(12") wide or narrower. Long rods are available for material up to 610mm(24") wide, and extra-long rods for work up to 915mm(36") wide. All aluminium parts are anodised black, except for the red bush carrier. The steel rods are ferro-blacked. Register pins, fixing and clamping knobs are turned brass with knurled heads. A 7mm sleeve-setting punch with hardwood handle is included. It will set the most common European support/sleeve combinations neatly without damaging the sleeve or upright. Eleven bushings are included with the jig: sizes 5, 6, 6.75, 7, 7.5, 8(5/16"), and 9mm, 7/32", 1/4", and 3/8" and an unhardened bushing. Please note: The long and extra long rods are available separately.