The CONTRINEX DW-AS-511-M18-002 is an inductive proximity sensor with tubular design, featuring an 18mm diameter chrome-plated brass housing and 63.5mm body length. This NPN sensor provides normally open output with 20mm sensing distance, non-flush mounting style, 500Hz switching frequency, and IP67 protection rating. It utilizes a 4-pin M12 quick-disconnect connector.