Features: 1.Easy Operation: When the signal gets the set times, the relay is closed, which can connect to the alarm, and you need to manually press the middle reset button before disconnection. 2.Counting Range: Enables a wide counting range from 1 to 999999, the digital counter makes the tallying much easier. 3.Free Connection: Equipped with NPN and PNP signal input port, can be flexibly connected to power supply, button, etc. 4.Extensive Using: Safe and reliable working with stability allows for wide application in equipment upgrading and DIY. 5.More Convenience: Both the maintenance and installation are very convenient, saving your time and labour as well. Item Type: Digital Counter Product Model: YF-16 Input voltage: 5~24V DC, 5~24V AC (all available). Counting Range: 1~999999 times Wiring Port Instruction: 1. AC DC +, -: Input power; 2. NPN: NPN signal input terminal; (can connect to power supply negative pole, button, sensor trigger, etc.) 3. PNP: PNP signal input terminal; (can connect to power supply positive pole, button, sensor trigger, etc.) 4. Output: The output is the passive contact switch value of the relay. 1 x Digital Counter