The Autonics PRL12-4DP is a long-distance cylindrical inductive proximity sensor for reliable non-contact detection of metal objects in industrial automation. Its 12 mm diameter metal housing and 4 mm sensing distance ensure stable detection of ferrous targets and easy mounting on machines. It uses a PNP output with normally open switching, providing positive sourcing current that interfaces cleanly with PLC and relay inputs. Built-in protection against reverse polarity and short circuits extends service life, and the sealed, rugged body resists dust, oil and vibration. With stable repeatability and fast response, the PRL12-4DP supports precise positioning, presence detection and counting in packaging, conveying and metalworking equipment.