Product Highlights Three levels of password protection Math functions for flow & round horizontal tanks 32-point, square root or exponential linearization Multi-pump alternation control Two or four relays & isolated 4 to 20 mA output options External 4-relay & digital I/O expansion modules RS-232, RS-422/485 serial communication options 12-24 VDC, 4 relays, 4-20 mA transmitter