Cressi Mini SPG The Mini Submersible Pressure Gauge luminescent dial reads from 0 to 5000 PSI (350 BAR) and is a must-have for any Scuba Diver. For at-a-glance monitoring of air pressure, the instruments face is divided into three different colored zones. The blue zone is the safety zone, indicating an air-pressure from 3000 to 5000 PSI (200 to 350 BAR). The scale in red indicated when the air is about to end. The alert zone is indicated with red stripes and is when the air pressure is below 600 PSI (50 BAR). The front glass lens is made to act as a pressure relief valve. n the event of a sudden increase in pressure inside the instrument, the glass rises slightly, allowing the excess pressure to escape. The Instrument is housed in a small, modern shaped boot, made from polycarbonate and Desmopan, to guarantee protection from shocks, scratches and ensure lightness. The Gauge Boot has an attachment point for a clip or lanyard. The Mini SPG is equipped with a 7/16" threaded high-pressure hose. The Mini SPG is developed and made in Italy by Cressi, a brand pioneer in Scuba Diving, Snorkeling and Swimming equipment.