Nikon AE-7C (30x) with circle, water-proof

High-performance automatic levels featuring airtight, dry-nitrogen-filled optics. Waterproof and fog proof, these instruments provide high accuracy in humid tunnels, unforgiving terrain and inclement weather. Key Features for AE-7C Automatic Level are Waterproof- The airtight, gas-filled (dry nitrogen gas) design of the telescope is perfect for wet or humid environments Nikon-Inches unique automatic compensator employs a wire-suspended pendulum and an air damper to prevent magnetic interference. And the wide compensation range (±16-Inch for AE-7C) makes it quick and easy to set up. Rugged construction provides excellent resistance to shocks. Highly accurate 1km double run leveling- AE-7C ±1.0mm without micrometer, ±0.45mm w/micrometer Optional high- and low-power eyepiece lenses- AE-7C High-power 37x, Low-power 19x Improved minimum focusing distance, down to 0.3m/0.98 Feet., for better performance in tight spots. Endless horizontal fine drive ensures smooth, precise pointing and angular measurement. To ensure rapid rotation, a new friction break does away with the need for clamps. Standard optical sight lets you find your target with precision and ease. Attaches to both flat- and spherical-head tripods. A mirror with a pentaprism lets you view the circular bubble as an erect image while setting up and sighting. The model AE-7C employs a 30x high-magnification.