This 1/4" NPT Milton micro filter is supplied with pre-assembled internal automatic overnight drain, which will operate when an air supply is shut down or when liquid has gathered in the filter bowl. The included 3 stage baffle system offers exceptional moisture removal. This micro filter includes a porous bronze sintered 40 micron filter element which allows less pressure drops and longer cleaning intervals. Micro filters remove harmful water or oil condensate, pipe scale, dirt and rust from compressed air systems and are used as pre-filters to coalescing type filters to ensure high efficiency and long element life. The corrosion resistant metal bowl has a capacity of 6 ounces. Maximum of 250 PSI and 48 SCFM. The included manual overnight drain has two functions; once the pressure drops the water drains from the bottom or it can also rotate the knurled knob on the drain to manually drain the water.