Allen-Bradley 440N-Z21X16H Digital I/O Module

The Allen-Bradley Guardmaster 440N‑Z21X16H is a non‑contact safety interlock switch in the 440N family, designed to monitor machine guarding doors and prevent access while equipment is energized. It features an 18 mm plastic barrel housing with no actuator included (the actuator is a separate component) and provides a six‑inch pigtail terminated to an eight‑pin Micro (M12) connector for compact, reliable wiring. The unit includes LED door indication/diagnostic and is part of the SensaGuard line of non‑contact interlocks, offering robust sensing without mechanical wear. This specific 440N‑Z21X16H variant is identified by the unique product code 440N‑Z21X16H, with appended numbers (A–Z) denoting configuration variations across regional or catalog options.