This gauge is different from the standard SPG due to the NEW PVD TREATMENT over the double chrome mirror plating of the case, to ensure the best looking and maximum protection against corrosion, in fact PVD is 300 times harder than chrome. On its back the gauge presents laser engraved specifications according to EN 250 and batch serial number. Brass housing with tempered glass gives extreme durability and chance to use with no cover protection due to double welding and copper beryllium bourdon tube mechanism that never goes out of calibration even with hard shock. The gauge is used often in technical diving and has a high level of accuracy and reliability. Preferred for its simplicity by many technical divers or divers who follow DIR training philosophy. Diameter 52 mm. Range graduation 0-360 bar.