# Spectra Precision GL720 Dual Grade Laser Package with HL700 Receiver
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Overview
The Spectra Precision GL720 dual-axis grade laser delivers precision slope control in two directions simultaneously, making it the ideal solution for complex grading projects requiring cross-slope and primary-grade references. This professional-grade rotating laser system features fully automatic self-leveling, rugged construction for harsh jobsite conditions, and industry-leading accuracy of ±1/16" at 100 feet. The included HL700 digital laser receiver provides clear visual and audible grade indication, allowing operators to work efficiently even in bright sunlight or over extended distances up to 2,600 feet diameter. Whether you're establishing drainage grades, preparing building pads, or setting dual-slope applications for parking lots and sports fields, the GL720 package provides the reliability and precision construction professionals demand.
Key Specifications
- Accuracy: ±1/16" at 100 feet (±0.8mm at 30m)
- Grade Range: -10% to +15% on both axes
- Working Diameter: Up to 2,600 feet (800m) with HL700 receiver
- Self-Leveling Range: ±5 degrees on both axes
- Rotation Speed: 600 RPM (10 Hz)
- Battery Life: Up to 60 hours continuous operation (alkaline D-cells)
- Operating Temperature: -4°F to 122°F (-20°C to 50°C)
- Receiver Detection Range: 2,600 feet (800m) diameter
- IP Rating: IP67 water and dust resistance
- Warranty: 3-year manufacturer warranty
What's in the Kit
- GL720 Dual Grade Laser Transmitter
- HL700 Digital Laser Receiver with Rod Clamp
- RC703 Remote Control with Holster
- Rechargeable Battery Pack and Charger
- Alkaline D-Cell Battery Tray
- Heavy-Duty Carrying Case
- Operator Manual and Quick Start Guide
- Calibration Certificate
Job Applications
- Parking Lot Construction: Simultaneously establish crown and longitudinal slopes for proper drainage without repositioning equipment, cutting layout time in half compared to single-grade lasers.
- Sports Field Grading: Create precise dual-axis drainage slopes for athletic fields, ensuring water runoff meets specifications while maintaining playable surfaces that prevent water pooling.
- Building Pad Preparation: Set exact elevation references across large foundation areas while controlling cross-slope, allowing excavation crews to achieve final grade in fewer passes.
- Drainage Channel Installation: Establish both invert elevation and cross-fall simultaneously for swales and ditches, eliminating the need for multiple setups and grade checks.
- Road and Highway Subgrade: Control superelevation and longitudinal grade at the same time for highway construction, improving accuracy and reducing surveying costs on DOT projects.
- Solar Farm Site Prep: Quickly establish consistent dual-axis slopes across large solar installation sites, ensuring proper panel array orientation and stormwater management.
Compatible Accessories
- GL700 Series Laser Receivers – Upgrade options with enhanced detection ranges
- Heavy-Duty Rod Clamps – Secure mounting for grade rods and poles
- Apache ATC Heavy-Duty Laser Tripods – Stable mounting for transmitter setup
- Spectra Precision Grade Rods – Telescoping and fixed-length options
- Laser Detector Poles – Extend receiver height for machine control
- Replacement Battery Packs – Extra power for extended projects
Related Guides
- Dual Grade vs. Single Grade Lasers: Which Do You Need?
- Understanding Laser Level Accuracy Specifications
- How to Set Dual Slopes with a Grade Laser
- Maximizing Laser Receiver Detection Range
FAQ
- What's the difference between the GL720 and single-grade lasers?
- The GL720 can establish slopes in two directions simultaneously (X and Y axes), while single-grade lasers only create slope in one direction. This makes the GL720 essential for applications like parking lots, sports fields, and roads that require both longitudinal and cross-slope control. Single-grade lasers would require repositioning or multiple units to achieve the same result.
- Can I use the GL720 as a standard rotary laser for level applications?
- Yes, absolutely. The GL720 functions as a high-precision rotary laser when both grade axes are set to 0%. This makes it versatile for foundation work, concrete forming, ceiling installation, and any application requiring a level reference plane. You're essentially getting dual functionality in one instrument.
- How far can the HL700 receiver detect the laser beam?
- The HL700 provides a working diameter of up to 2,600 feet (800 meters) under ideal conditions. Actual detection range varies based on ambient light, atmospheric conditions, and receiver battery strength. For most construction applications, you'll achieve reliable detection at 1,500-2,000 feet diameter even in bright sunlight.
- Does the GL720 require daily calibration or setup?
- No daily calibration is needed. The GL720 features automatic self-leveling that activates each time you power on the unit, typically completing in 30-60 seconds. Spectra recommends professional calibration verification annually or if the unit experiences a significant impact. The included RC703 remote control allows you to adjust grades from up to 300 feet away without returning to the transmitter.
