This box joint jig is really cool since it enables you to cut different sized box joints using a single blade. It's relatively easy to put together and it works really well. This jig is an attachment to my previous table saw cross cut sled, which I've made a very detailed Instructable about:How To Make a Cross Cut Sled. You can either add on to that sled using these specific parts and dimensions, or you can use the general concepts and ideas and add on to your existing table saw sled.