This listing is for a replacement photoelectric sensor, model E3FA-TN21, supplied as a single unit. The sensor is a through-beam type with a seller-listed sensing distance of 20 m, NPN output, and an operating voltage range of 10-30 V DC. It is intended for use in industrial sensing tasks such as conveyor object detection and machine automation.

• Sensing type & range: Through-beam photoelectric sensor with a seller-listed sensing distance of 20 m.
• Electrical: NPN output with operating voltage 10-30 V DC (seller attributes).
• Package contents & notes: Includes 1 sensor (model E3FA-TN21). Product image shows the sensor label; other equipment or mounting hardware is not included.