The Spectra Precision LL300N-81 is a field-ready grading package built for professional contractors who need dependable horizontal leveling right out of the box. By bundling the LL300N rotary laser with the HR320 laserometer receiver, a heavy-duty tripod, and a tenths-scaled grade rod, this kit eliminates the procurement headaches of assembling a grading system piecemeal — a genuine advantage when building bench crews, replacing storm-damaged gear, or standing up a new crew truck.
System Overview & Jobsite Applications
The LL300N-81 is engineered around the workhorse LL300N self-leveling rotary laser, which delivers a highly visible 635nm red beam across a 2,000-foot diameter working range. Whether you are establishing finish grades for a slab pour, checking subgrade elevation across a large earthwork site, or setting batter boards for a residential foundation, this system provides the accuracy and range to keep your crew moving. The integrated self-leveling compensator locks in a true horizontal plane in seconds, reducing setup time and eliminating costly re-checks caused by out-of-level instrument errors.
Key Specifications
- Accuracy: ±1/16 inch at 100 feet (±1.5mm at 30m)
- Self-Leveling Range: ±5 degrees automatic compensator
- Working Range: Up to 2,000 ft diameter (with HR320 receiver)
- Rotation Speed: 150, 300, or 600 RPM selectable
- Laser Class: Class IIIa / Class 3R, 635nm visible red
- Battery Life: Up to 100 hours on 4 D-cell alkaline batteries
- Grade Rod: 16-foot fiberglass rod with tenths-foot graduation
- IP Rating: Dust and water resistant for outdoor jobsite use
What's in the Kit
- Spectra Precision LL300N Rotary Laser Level — self-leveling horizontal plane laser with out-of-level alarm
- HR320 Laserometer Receiver — dual-sided display with audible and visual grade indicators, compatible with all major rotary laser brands
- Heavy-Duty Tripod — contractor-grade aluminum tripod with wide stance for stable setup on uneven ground
- 16-Foot Tenths Grade Rod — fiberglass construction with clear tenths-foot markings for fast elevation reads alongside the HR320
- Carrying Case — molded protective case for secure transport and storage of the laser head and accessories
- 4 D-Cell Batteries — pre-installed for immediate field use
- Operator's Manual & Warranty Card
Job Applications
Slab & Foundation Grading: Set the LL300N on the tripod, lock in your benchmark elevation, and walk your crew through finish grade checks using the HR320 on the tenths rod — no calculator needed when your rod already speaks in tenths.
Earthwork & Sitework: The 2,000-foot working diameter keeps the instrument stationary while equipment operators and grade checkers work across large cut-and-fill sites without constant instrument moves.
Utility & Pipeline Slope: While the LL300N is a horizontal-plane laser, crews use it to establish consistent invert elevations at manholes and inlet structures by shooting to a known benchmark and transferring grades via the tenths rod.
Landscaping & Drainage: Lawn grading, swale establishment, and patio drainage slopes are fast and repeatable when the entire kit is staged on a single tripod setup near the work area.
Compatible Accessories
- Spectra HR320 Replacement Receiver
- Spectra LD-8 Laser Detector for Bright Conditions
- Heavy-Duty Laser Level Tripod (Replacement)
- 16-Foot Fiberglass Grade Rod (Tenths)
- Spectra LL300N Carrying / Replacement Case
- Grade Rod Clamp for HR320 Receiver
Related Guides
- How to Set Up a Rotary Laser Level for Slab Grading
- HR320 Receiver Quick-Start Guide
- Reading a Tenths Grade Rod: Contractor Field Reference
- Rotary Laser Level Comparison: LL300N vs. LL500
Frequently Asked Questions
- Does the LL300N-81 work for slope or grade mode applications?
- The LL300N is a single-axis self-leveling horizontal laser and does not include a manual grade or dual-axis slope mode. For controlled slope applications, consider the Spectra LL400 or HL700 series. The LL300N excels at flat horizontal plane work including slab grading, foundation layout, and elevation transfer.
- Can the HR320 receiver be used with other laser brands on the jobsite?
- Yes. The Spectra HR320 is a universal laserometer receiver compatible with virtually all 635nm and 670nm red-beam rotary lasers, including Trimble, Leica, Topcon, and DeWalt rotary units. This makes it a versatile backup receiver across mixed-brand crew setups.
- What is the warranty on the LL300N-81 kit?
- Spectra Precision covers the LL300N laser with a 3-year manufacturer warranty on parts and labor. The HR320 receiver and mechanical accessories carry a 1-year warranty. Express Tools is an authorized dealer, so warranty service can be initiated directly through us or through any Spectra Precision service center.
- Is the tenths grade rod in this kit compatible with metric or engineer's scale readings?
- The grade rod included in the LL300N-81 kit is graduated in US survey feet and tenths of a foot, which is the standard for most North American civil construction and earthwork applications. It is not a metric or architect's-scale rod. If your project specs call for metric readings, a separate metric rod would be required.
Frequently Asked Questions
Does the LL300N-81 work for slope or grade mode applications?
The LL300N is a single-axis self-leveling horizontal laser and does not include a manual grade or dual-axis slope mode. For controlled slope applications, consider the Spectra LL400 or HL700 series. The LL300N excels at flat horizontal plane work including slab grading, foundation layout, and elevation transfer.
Can the HR320 receiver be used with other laser brands on the jobsite?
Yes. The Spectra HR320 is a universal laserometer receiver compatible with virtually all 635nm and 670nm red-beam rotary lasers, including Trimble, Leica, Topcon, and DeWalt rotary units. This makes it a versatile backup receiver across mixed-brand crew setups.
What is the warranty on the LL300N-81 kit?
Spectra Precision covers the LL300N laser with a 3-year manufacturer warranty on parts and labor. The HR320 receiver and mechanical accessories carry a 1-year warranty. Express Tools is an authorized dealer, so warranty service can be initiated directly through us or through any Spectra Precision service center.
Is the tenths grade rod in this kit compatible with metric or engineer's scale readings?
The grade rod included in the LL300N-81 kit is graduated in US survey feet and tenths of a foot, which is the standard for most North American civil construction and earthwork applications. It is not a metric or architect's-scale rod. If your project specs call for metric readings, a separate metric rod would be required.