Keep critical spaces under watch with a modular dry-contact sensor designed for door and equipment monitoring. The Vertiv SN-3C connects to compatible Liebert MPX and MPH PDUs, giving infrastructure teams a simple way to detect status changes at the point where access matters most. Its three dry-contact input design supports a single probe configuration, making it well suited for focused monitoring of doors, enclosures, or other discrete contact points. The included 50 ft cable provides practical reach for real-world installations, while the compact sensor form factor helps it fit cleanly into dense rack and facility layouts. For teams managing data processing, healthcare, or industrial environments, this sensor adds a layer of visibility without adding complexity. It is built for deployments where knowing whether a door is open or closed is part of maintaining uptime, compliance, and physical security discipline. Backed by a 1-year limited warranty, it is a purpose-built accessory for environments that demand reliable status monitoring.