Spectra Precision Lasers / Trimble HR320 Hr320 Receiver with C59 Rod Clamp Large, easy to read, LCD on front and rear make it ideal for exterior applications and a loud 100db speaker can be heard on noisy job sites Includes a C59 rod clamp which offers a snap in feature for quick switching between rod mounted and handheld applications Rugged, waterproof housing withstands 5ft (1.5m) drops and protects the unit against moisture and dust Class 1 Laser and &lt;1mW (less than 1 Milliwatts)