C	Crystal Time Base: A crystal reference is employed for those applications requiring independence from the line frequency. A trimming function is included for greater accuracy (2-3 seconds/week).
J	220 VAC/50 Hz Operation: The unit is configured to operate from 220 VAC line voltage. 117 VAC 50/60 Hz is standard.
N	Reverse Count at Zero: Changes count direction from Down to Up at Zero.
UL	"UL" Approved Power Supply: The unit is supplied with a UL/CSA approved wall mount power supply.
V	DC Power: 12 VDC Power Input replaces 110 VAC. Voltage on ES-370 & ES-570 is 5 volts; all others are 12 volts (including option 'T' on ES-570U).
W	3-Wire Power Cord: Recommended where static charges can occur. Standard on many units, otherwise a 2-wire cord is supplied.
Y	Relay Closure at Zero: Reed Relay for Control Applications (10W max load; 500ma switching current).
Z	Stop with reed relay closure at Zero (10W max load; 500ma switching current).