Bosch Professional GRL 400 H Self-Levelling Horizontal Rotary Laser

The Bosch Professional GRL 400 H is a self-levelling horizontal rotary laser for construction, groundwork, and outdoor levelling applications. It projects a red laser beam rotating at 600 RPM to establish a continuous horizontal reference plane for setting elevations and aligning foundations. With a compatible receiver, the rotary laser supports a working range of up to 400 m, making it practical for large outdoor sites. The electronic self-levelling system compensates for setup deviations within a 5° range and achieves a levelling accuracy of 0.08 mm/m. A shock-warning system alerts the user if the instrument is disturbed during operation.

The IP56-rated enclosure resists dust ingress and water jets for reliable performance on exposed construction sites. Power comes from two LR20 (D) batteries, providing up to 30 hours of continuous operation on a single set. A 5/8-inch tripod thread enables mounting on standard surveying tripods for stable positioning over uneven ground. The blue and black unit houses a Class 2 laser emitter. Two batteries are included for immediate use on site.

• 635 nm laser wavelength – produces a visible reference beam in varied lighting conditions
• Self-levelling completes in 15 seconds – minimises idle time during setup
• 180 × 190 × 170 mm dimensions – compact footprint for transport between locations
• 2 kg total weight – practical for tripod mounting and repositioning
• 20–400 m working range – covers close-range visibility to extended outdoor coverage with a receiver