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