Check the listing for details. 100mv, 200mv Panel Meter Digitally Scaleable RS232, RS485. Condition: New. Listed at 13.95 USD. Compare to meters costing > $100 -- can be digitally scaled to display its measurement in YOUR units, not just volts! Example: other 0-100mv meters show 0 to 100.0 and you can move the decimal point or scale (down only) with a pot. CDPM lets you digitally scale/offset the display separately from the measurement so the 0-100mv meter can display that as 0 to 100.0, or 0 to 2500, or even -75 to 9975 -- no pots to adjust. Plug it into a PC's USB port with an adapter, or a COM port (using a Config Cable sold separately) and with a few simple entries, download the 8-decimal digit scale/offset factors. CDPM then shows the actual gallons in a tank or microns of thickness or altitude of a rocket -- anything you want within the -9999 to +9999 range (w/adjustable decimal pt). Full scale input ranges available from 50mv to 100VDC plus 4-20mA.Programming is not required. As delivered, the CDPM is scaled to display volts, so out-of-the-box it operates autonomously like other meters. Unplug it from the PC and it operates autonomously like other meters. -- OR -- Keep it connected to a serial host and from hundreds (RS232) or thousands(RS485) of feet away, dynamically re-scale/offset the meter in an instant to change from gallons to cubic feet, microns to inches, or flash the display, show a cryptic text message*, or query the meter to return its measured value for logging or process control. These are truly versatile meters that can operate out of the box as standard volts-displaying meters, or be reconfigured as needed. Configuration is ... simple. The Cerrxian USB-RS485 converter pictured is NOT included with the purchase of the CDPM -- the pic shows a simple example of connecting to a USB port. Versalent or Modbus RTU/ASCII protocol Test drive and configure a demo meter online at www.versalent.biz?P=cdpmsim.htm See the datasheet and full manual at www.versalent.biz?P=cdpm.htmPanel cut-out 1.04" X 1.82"Volume pricing at www.versalent.biz *Shows the limited characters that can be emulated with a 7-segment display, like 'Err9', 'CFLL' see manual.