Your search for "pwr-ms420-400ac-r" revealed the following:
NEW Cisco Meraki PWR-MS420-400AC-R 400W AC Front-to-Back Switch Power Supply
SKU: NSN-8234
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Cisco Meraki PWR-MS420-400AC-R 400W AC Front-to-Back Airflow Switch Power Supply
SKU: NSB-6981
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days