New style Desiccant Drying System with rod in the bowl makes for easy desiccant replacement Delivers extremely dry compressed air as low as -30¿F dew point without using electricity or refrigeration Easy to monitor, when color changes in the sight glass from dark blue to pink, then it is time to change or dry the desiccant Initial supply of desiccant included Pipe Size: 1/2" Max Flow: 30 SCFM Desiccant Charge: 1 gal.