The GRS-16PE D guide rail square fits DeWalt guide rails. Made from solid aluminium, CNC machining ensures extreme accuracy and allows you to achieve dead square cuts with your DeWalt track saw. Slide the square into the T-slot of your guide rail and close the latch, setup is as simple as that. The GRS-16PE D guide rail square features two reference edges. The advantage of this feature is it allows you to reference using either the front or back edge of the workpiece depending on the situation. For instance, when cutting kitchen worktop, you can use the rear square edge rather than the rolled front edge to guarantee an accurate result. The ability to reference either the front or back edge gives you flexibility as to the direction of your cut. As in most cases, it is better to have your workpiece underneath the guide rail and the waste on the opposite side. The 400mm long reference edges are at precisely 90° to your track. There is a small notch in the front of each reference edge to allow you to use a guide rail clamp for extra security should you so wish. Once fitted this guide rail square allows you set your guide rail at a perfect 90°, in an instant, every time.-bg