3000 psi, adjustment at 1500 psi. Unused and very clean, like new. Not sure how it works since there's only one port. Probably blows apart. Unused and very clean.
Oil pressure forces a spring loaded red piston forward to show presence of system pressure.
Has double O-ring seals and apparently can be safety wired. Unused and very clean. But its friends call it 37-1 for short. Clean used condition. Get a Synergetics catalog .