Check the listing for details. DC 12V 24V 4-digit Digital Counter Module Time Control Board With Relay Output. Condition: New. Listed at 5.98 USD. Signal mode: low level valid ( Connect to NPN-NO sensor, or common push button switch). - when the counting reaches the set value, the relay will turn off. During the pause state, pressing this key will enter the continue state (relay turns back on), responding to the count.