Keep EX4100-H access switches running through planned maintenance and power events with a Juniper 340 W AC power supply designed for the EX4100-H-12MP-AC platform. This unit is built for environments where uptime, thermal consistency, and serviceability matter more than commodity pricing. The front-to-back airflow pattern aligns with standard data center and wiring closet cooling paths, helping preserve rack-level airflow discipline. Hot-swap support lets teams replace the supply without taking the switch out of service, which is critical when the access layer carries voice, wireless, and endpoint traffic. For infrastructure teams standardizing on Juniper EX switching, this PSU provides the right fit for the chassis rather than a generic replacement. That matters when you need predictable integration, cleaner maintenance workflows, and fewer compatibility questions during procurement. Choose this power supply when the cost of downtime exceeds the cost of the part. It is a practical fit for production access networks that need dependable power delivery and straightforward field replacement.