The 5ive Star Gear Marching Lensatic Compass is liquid filled with fluid to protect against excessive swing or wobble, improving readability while reducing wear. The compass also features a slide ruler, magnifying glass, and a sturdy metal case.FeaturesSturdy metal case with luminous letteringLiquid filled for easy reading and reduced wearDual scales in both mils and degreesScale 1:50,000 metersIncludes a built-in slide ruler and magnifying glass