The Staun automatic tire deflator is a spring loaded check valve with the ability to vary the spring pressure on the check valve via the Adjustment Cap. More spring pressure means a higher destination*, shut OFF pressure. Less spring pressure means a lower destination pressure. The SCV5 has a destination pressure range range of about 6 to 30 PSI and an adsutment rate of about 6 or 7 PSI per revolution of the Adjustment Cap. The SCVLD has a destination pressure range of about 0 to 10 PSI and an adjustment range of about 4 or 5 PSI per turn. The SCVHD has about a 15 to 55 PSI destination range with an 8 or 9 PSI per turn adjustment rate
The Adjustment Cap is held in place by the Lock Collar. Never use pinching tool like pliers or vice grips for they may distorte the Main body and cause the deflator to malfunction. This voids the warranty.
TEMPERATURE INCREASE ADJUSTMENTS: As tires warm up, the pressure increases. To pick up that increase from a cold morning start, just screw the deflator back on the tire valve stem, pull the Manual Start Notch and wait for it to shut OFF. Expect only a few seconds of air flow since this is typically a small pressure increase.
All Staun automatic tire deflators come it sets of 4 deflators, a leather carrying case and setting and use instructions.