Brunton's O.S.S. 30B Baseplate Compass features (Orbital Sighting System) technology that sets a new standard for precision and accuracy while retaining ease of use. The long straight edge lets you easily draw navigation lines on your map and the magnifier and interchangeable scale cards- all help you stay on course. Meridian lines at map level aid orientation with a map and minimize distortion.

• BRUNTON O.S.S. alignment system
• Tool free declination adjustment shows the difference between magnetic and true north~ so you can get the most accurate readings
• Meridian lines at map level aid orientation with a map and minimize distortion
• 2 degree resolution
• Extra long straight edge lets you easily draw navigation lines on your map
• Map Magnifier
• Inch/mm scales
• Interchangeable scale cards
• Lanyard
• Size: 2.9?x4.2?x0.6?
• Weight: 1.8 oz.