This is a Panasonic M18 0.1m Range PNP Photoelectric Diffuse Reflective Sensor with a 2M Cable. Its part number is CY-121A-P.

Specifications:

• Cable Length: 2 m
• Connection Type: Cable
• IP Rating: IP67
• Light Source: Infrared
• Maximum Operating Temperature: 55 C
• Minimum Operating Temperature: -25 C
• Output: PNP Open Collector
• Response Time: 1 ms
• Sensing Mode: Diffuse
• Series: CY-100 Series
• Supply Voltage: 12-24 VDC
• Type: Reflective Sensors