Modest price. Military. The only difference is this version employs a phosphorescent paint for lightless visibility instead of self-luminous Tritium. Specifications for Cammenga Phosphorescent Lensatic Compass 27 - Southern Hemisphere: Fabric/Material: Powder Coated Aluminum Weather Resistance: Shock Resistant Water Resistance Level: Water Resistant Features of Cammenga Phosphorescent Lensatic Compass 27 - Southern Hemisphere Shockproof damage-resistant design. Waterproof to considerable depths. Sandproof for extra durability. Accuracy +/- 40 mils. Performs flawlessly in temperatures ranging from -50 F to 150 F. Uncompromised by temperature changes due to its non-liquid filled needle housing. Uses a copper induction-damping ring that slows settles and steadies the compass needle quickly. Constructed with a powder-coated aluminum frame for optimal endurance.