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).
D	Remote Control: This option consists of a connector wired to switches on a control plate via a six-foot cable. Extra cable available.
HR	Relay Contact Closure: A contact closure occurs at the top of each Hour. Hour and 1/2 Hour closure may be ordered on some products. Relay contacts are rated at 10-Watts maximum load, 500mA maximum switching current.
J	220 VAC/50 Hz Operation: The unit is configured to operate from 220 VAC line voltage. 117 VAC 50/60 Hz is standard.
RS	RS-232C Output: Computer Interface allows the time code data to be shared with a computer.
UL	"UL" Approved Power Supply: The unit is supplied with a UL/CSA approved wall mount power supply.