2.5" Inches Approximate Military brass compass solid brass engineering prismatic compass easily folds and the lid opens and the front prismatic sight folds over the compass to function as the front sight. The prism has a magnifier to allow viewing the compass card and the object being sighted simultaneously. The front sight has a magnifier to simultaneously view the magnetic heading when taking a sight. Folding the sight down operates a needle lift mechanism to protect the compass bearing. On the side of the compass is a needle freeze mechanism to hold a reading. Antique collectible magnetic compass very nice for marine gift This product is very durable and safe. Working model takes accurate reading for hiking or navigation This advanced Compass is highly durable as it is strongly built to last for a long period of time. Measuring vertical angles with clinometer ~ Defining points of the same elevation ~ Measuring strike and dip Brunton compass, properly known as the Brunton Pocket Transit, is a type of precision compass. Unlike most modern compasses, the Pocket Transit utilises magnetic induction damping rather than fluid to damp needle oscillatio Additional Details ------------------------------ Product description: 2.5" Inches Approximate Military brass compass solid brass engineering prismatic compass easily folds and the lid opens and the front prismatic sight folds over the compass to function as the front sight. The prism has a magnifier to allow viewing the compass card and the object being sighted simultaneously. The front sight has a magnifier to simultaneously view the magnetic heading when taking a sight. Folding the sight down operates a needle lift mechanism to protect the compass bearing. On the side of the compass is a needle freeze mechanism to hold a reading. Antique collectible magnetic compass very nice for marine gift This product is very durable and safe. Working model takes accurate reading for hiking or navigation This advanced Compass is highly durable as it is strongly built to last for a long period of time. Measuring vertical angles with clinometer ~ Defining points of the same elevation ~ Measuring strike and dip Brunton compass, properly known as the Brunton Pocket Transit, is a type of precision compass. Unlike most modern compasses, the Pocket Transit utilises magnetic induction damping rather than fluid to damp needle oscillatio