Brunton Compasses F-8040G Trustworthy, is the word for this compass, It is a mirrored map compass with an easy-reading optic green base-plate. Tool-free declination adjustment makes it easy, and the built-in thermometer gives you information that most compasses do not. 3.8"x2.5"x.9" 1.6 oz. 2° graduations 0-35° inclination scale Declination adjustable Clinometer Inch & mm scales Lanyard Thermometer Weight: 4 oz.