Laserline Mfg. Inc. is the world's largest manufacturer of direct reading (Lenker style) grade rods, which feature a movable tape face allowing you to set the actual benchmark elevation, or any elevation, above or below the bench into the rod. Laserline detector brackets attach to the special rail slide on laser grade rods. Made of rugged, lightweight extruded aluminum with a black anodized finish. View/download Detector to Bracket Match Guide.