Details "SPG'S"The SPG 52 MM or SPG 60 MM is the perfect pressure gauge for any dive. Choose from 360 Bar or 5.500 PSI. The tempered mineral glass, nearly scratch resistant, extends the life of your pressure gauge. The durable brass nickel plated body can be used with our without a boot. Highly visible phosphorescent bezel allows for easy pressure reading in any environment. And comes with a double ended o ring air spool for swivel hose installation.