Overview for LaserLine B1-T Alumnimum Bracket for Trimble HR400, HR500 and CR600 Laser Detectors The LaserLine B1-T Detector Bracket is compatible with Trimble HR400, HR500 and CR600 laser detector models. It is lightweight and constructed of extruded aluminum in black anodized finish. This bracket allows the laser detector to travel the full working length of the grade rod through its special rail. The LaserLine B1-T Detector Bracket attaches to any LaserLine Direct Reading laser rod. It allows for faster and easier readings without the need of having to loosen, move and then tighten the detector.