Set Two Independent Grades Simultaneously with the Spectra GL422N-29
The Spectra Precision GL422N-29 is a professional dual slope grade laser system purpose-built for contractors who can't afford to re-stake or reset mid-job. Whether you're cutting building pads with compound slopes, designing positive drainage across a parking lot, or coordinating subgrade work across a large site, the GL422N lets you lock in two independent grade percentages at once — saving time, reducing crew confusion, and delivering the accuracy that paving and grading professionals demand. This complete package bundles the GL422N laser head with the HL760 grade receiver, a telescoping grade rod, and a heavy-duty tripod so you're ready to work straight out of the box.
System Overview & Jobsite Applications
Dual slope lasers occupy a critical tier above entry-level single-slope machines. On jobs where X-axis and Y-axis grades must both be controlled — think athletic fields, retention basins, warehouse slabs, or road crown work — a single-slope instrument forces multiple setups and introduces compounding error. The GL422N eliminates that by projecting a rotating laser plane tilted in two axes simultaneously. The HL760 receiver reads the beam at up to 2,600 ft (800 m) range, displays numeric grade readout, and gives audible and visual cut/fill guidance so operators on the machine or the rod don't need to radio back for confirmation.
Key Specifications
- Grade range: ±10% on both X and Y axes simultaneously
- Accuracy: ±1.5 arc seconds (self-leveling range ±5°)
- Receiver working range: up to 2,600 ft (800 m) diameter
- Rotation speed: 300, 600, or 1,200 RPM selectable
- Remote control: RC402N wireless remote included for grade adjustment from the machine cab
- Battery life: up to 100 hours on 4 D-cell alkaline batteries
- IP66-rated laser head — dust-tight and protected against water jets
- Operating temperature: -4°F to +131°F (-20°C to +55°C)
- Receiver: HL760 with numeric grade display and ±0.01% grade readout resolution
What's in the GL422N-29 Package
- Spectra Precision GL422N dual slope rotating laser head
- HL760 grade laser receiver with display bracket and clamp
- RC402N wireless remote control
- Telescoping grade rod (fiberglass, metric/imperial)
- Heavy-duty contractor tripod with quick-release head
- 4 D-cell batteries
- Carrying case for laser head and accessories
- 2-year Trimble/Spectra Precision warranty
Job Applications
Building Pad & Foundation Prep: Set both longitudinal and cross slopes in a single instrument setup. Blade operators receive continuous grade guidance across the entire pad without the supervisor resetting the laser between passes.
Parking Lot & Hardscape Drainage: Positive drainage design on commercial paving jobs requires holding two slopes to keep water moving toward catch basins. The GL422N maintains both simultaneously across large paving runs.
Athletic Field Grading: Sports field specs typically call for a crowned or compound-sloped surface within tight tolerances. Dual slope capability keeps finish grading on spec without repeated instrument moves as the dozer or motor grader works across the field.
Roadway Crown & Ditch Work: Establish road crown or ditch-line grade references across long road sections. The long-range receiver performance means one instrument setup covers a full station run without moving the tripod.
Compatible Accessories
- HL760 Replacement Grade Receiver
- RC402N Wireless Remote Control
- Spectra Precision Contractor Tripod
- Replacement Grade Rod — Fiberglass
- GL422N Carrying & Storage Case
- Machine Mount Bracket for HL760 Receiver
Related Guides
- How to Set Dual Slope on the Spectra GL422N — Step-by-Step
- Single Slope vs. Dual Slope Grade Lasers: Which Do You Need?
- Grade Laser Range & Accuracy Guide for Earthwork Contractors
- Setting Up a Grade Laser on a Tripod for Building Pad Work
Frequently Asked Questions
- Can the GL422N-29 be used for machine control?
- The GL422N is designed for grade rod and staff use with the included HL760 receiver. It is not a machine-control laser in the GPS/total station sense, but the HL760 receiver can be bracket-mounted to a grade rod on a skid steer or motor grader for operator-guided grading. For fully automated blade control, a dedicated machine control system is required.
- What is the difference between the GL422N and the GL422N-29?
- The model suffix (-29) designates the specific package configuration sold by authorized dealers. The GL422N-29 includes the GL422N laser head, HL760 receiver, RC402N remote, grade rod, and tripod as a bundled kit. The laser itself is identical across package variants.
- How do I set a specific grade percentage on the GL422N?
- Grade is set using the front-panel keypad or wirelessly via the RC402N remote. Enter the desired X-axis and Y-axis grade values independently using the numeric input. The instrument's self-leveling system establishes a level baseline and then tilts the laser plane to your entered values. Always verify against a known benchmark before beginning work.
- Is the GL422N-29 covered under warranty if purchased from Express Tools?
- Yes. Express Tools is an authorized Spectra Precision dealer. The GL422N carries a 2-year manufacturer's warranty through Trimble/Spectra Precision when purchased from an authorized source. Proof of purchase from Express Tools satisfies the authorized dealer requirement for warranty service.
