David White LT8-300LP Universal Level-Transit with Laser Plummet

The Spectra GL1425C-27 is a professional-grade dual-slope laser system engineered for contractors and site superintendents who demand precision, speed, and reliability on demanding civil and building construction jobsites. This complete inch-based package pairs the GL1425C laser with the HL760 deluxe receiver, a heavy-duty tripod, and an inch-graduated grade rod — everything your crew needs to establish and verify grade from the first setup to final inspection.

System Overview & Jobsite Applications

The GL1425C broadcasts a high-visibility laser plane that self-levels within its compensator range and accepts independent dual-axis grade input up to ±10% on both the X and Y axes simultaneously. Bluetooth wireless connectivity allows the instrument operator or grade checker to adjust slope settings remotely from up to 200 feet away using the RC602 remote, reducing crew requirements and keeping workers out of traffic-exposed instrument zones. The inch-graduated rod in this 27-series package is purpose-built for U.S. standard construction workflows, aligning directly with Imperial-unit site plans and eliminating on-the-fly unit conversions during field note documentation. Whether you are grading a parking structure deck, establishing finished floor elevation for a tilt-up building, or setting slope on a storm drain swale, the GL1425C-27 delivers the accuracy and workflow efficiency that professional crews expect.

Key Specifications

• Accuracy: ±1/16 in at 100 ft (1.5 mm at 30 m)
• Grade Range: ±10% on both X and Y axes simultaneously
• Self-Leveling Range: ±5°
• Operating Range: Up to 2,000 ft diameter (600 m) with HL760 receiver
• Rotation Speed: 100, 300, and 600 RPM selectable
• Wireless Control: Bluetooth RC602 remote compatible (up to 200 ft range)
• Power: Internal rechargeable battery; up to 30 hours runtime
• IP Rating: Weather-resistant construction for outdoor jobsite use
• Rod Graduation: Inch-based (27-series)

What's in the Kit

• GL1425C Dual-Grade Rotating Laser — the core instrument with onboard grade drive and Bluetooth module
• HL760 Deluxe Laser Receiver — large 5-inch detection window, audible and visual grade indicators, magnetic bracket for rod mounting
• Heavy-Duty Tripod — aluminum construction, wide stance base for stable setup on soft or uneven ground
• Inch-Graduated Grade Rod — U.S. standard Imperial graduation for direct read-out with American site plans
• Rechargeable Battery Pack & Charger
• Carrying Case — hard-shell instrument case for transport and storage

Job Applications

Parking Lot & Parking Structure Grading: Set precise cross-slopes and drainage grades across large paved areas. The dual-grade capability lets you program both longitudinal and transverse slopes in a single setup, reducing instrument moves and keeping paving crews productive.

Building Pad & Finished Floor Elevation: Establish and verify subgrade and finished floor elevations for tilt-up, masonry, and wood-frame construction. The HL760 receiver gives finish carpenters and concrete crews a fast, audible-confirmation grade check without calling the instrument operator.

Utility & Storm Drain Installation: Control pipe invert elevations and trench bottom grades for gravity-flow systems. The extended 2,000 ft operating range keeps the laser out of the active excavation zone while maintaining consistent grade reference throughout the run.

Road Base & Site Earthwork: Use the GL1425C-27 with a machine-mount receiver bracket to guide motor graders and compactors during rough and finish grading operations, reducing pass counts and improving compaction uniformity across the pad.

Compatible Accessories

• RC602 Bluetooth Remote Control — adjust grade and rotation speed from the rod location
• HL760 Replacement Receiver — spare receiver for large crews or multi-machine operations
• Spectra Grade Rod Extensions — extend reach for deep excavation or elevated slab work
• Machine Mount Bracket Kit — compatible bracket for dozer and grader receiver mounting
• Spectra Replacement Battery Pack — keep a spare charged for all-day operations

Related Guides

• How to Set Dual Grade with the Spectra GL1425C
• Choosing the Right Laser Receiver for Grade Work
• Inch vs. Metric Grade Rods: Which Package Is Right for Your Project?
• Site Grading Laser Level Buyer's Guide

Frequently Asked Questions

Can the GL1425C-27 set independent grades on both axes at the same time?

Yes. The GL1425C supports simultaneous dual-axis grade input, allowing you to dial in separate X-axis and Y-axis slopes — up to ±10% each — in a single instrument setup. This is especially useful for parking lot cross-slopes and crowned roadway profiles where both longitudinal and transverse grades must be controlled concurrently.

What is the difference between the GL1425C-27 and the GL1425C-14 package?

The primary difference is the grade rod included in the kit. The -27 suffix designates an inch-graduated rod suited to U.S. Imperial workflows, while the -14 suffix indicates a metric-graduated rod. The laser instrument, HL760 receiver, and tripod are the same across both packages. Select -27 if your site plans and survey notes are in feet and inches.

How far away can I operate the GL1425C with the Bluetooth remote?

The RC602 Bluetooth remote control operates at ranges up to approximately 200 feet (60 m) in open conditions. This allows a single operator to adjust instrument grade settings, rotation speed, and power from the rod location without walking back to the instrument — a significant time saver on large pads and during finish grading operations.

Is the GL1425C-27 compatible with machine control receivers for grading equipment?

The GL1425C is compatible with a range of machine-mount laser receivers when used with the appropriate bracket kit. While it is not a full digital machine control system, it can effectively guide motor graders, dozers, and compactors using a mast-mounted receiver for efficient rough and finish grading without a full GPS/machine control investment.