Pro Shot AS2 Magnum Laser Level with R8 Detector | Benchmark Online LLC
Slope efficiency, explained by RP Photonics Encyclopedia; laser, differential efficiency
Topcon RL-SV1S Rotating Grade/Slope Laser
Agatec GL1000 - Dual Grade / Slope Laser | Innovative tools for the trade
Spectra Precision GL612N Single-Slope Grade Laser with HL760 Digital Readout Receiver, C70 Rod Clamp, RC602 Remote Control, 10 Ah NiMH Batteries, Charger, and hard carrying case - - Amazon.com