DEF digital UL meter, engineered polymer in line turbine meter that may be installed at the end of a hose or plumbed in a fixed pipe installation with the 1" NPT inlet/outlet, use for DEF, agriculture chemicals, non-potable water, & many other chemical applications, 20 pre-set calibration factors based on fluid type or can be easily calibrated in the field, uses 2 "AA" batteries that can be easily changed when needed, a low battery level alert will notify the user when it is time to change the batteries.