This is a Panasonic Through-Beam Optical Sensor. It's part number is CY-111A.

Specifications

• Manufacturer: Panasonic 
• Part Number: CY-111A
• Series: CY-100 
• Sensing Method: Through-Beam
• Sensing Distance: 590.551" (15m)
• Voltage - Supply: 12V ~ 24V
• Response Time: 1ms
• Output Configuration: NPN - Open Collector
• Connection Method: Cable
• Ingress Protection: IP67
• Cable Length: 78.74" (2m)
• Light Source: Infrared
• Operating Temperature: -25°C ~ 55°C