Bosch optical level GOL26D professional extremely robust ideal for outdoor use designed for outdoor use due to sturdy metal housing with dust and splash protection (ip54) robust design with built in target collimator and integrated circular vial compensator lock for safe transport target collimator for rough alignment penta prism makes it easy to read the circular vial large focusing knob for easy alignment fast aperture for excellent staff reading high precision (1mm/30 m) over long distances endless degree/angle setting using knobs on both sides with friction braked rotation erect image technical specifications unit of measure: 360 degrees leveling accuracy: 1mm at 30 m tripod thread: 5/8 inch length: 215 mm width: 135 mm height: 145 mm. Set consists of GOL26D auto level, heavy duty tripod stand & 5m leveling staff.