The Catalyst 4500 Series Dual Input AC Power Supply supports data and PoE, is designed to accept either 100V AC circuits or 200V AC circuits. The 4200W supply is the largest internal AC power supply available for the Catalyst 4500 series switch. Customer planning large scale PoE deployments can use the dual inputs in the 200V AC configuration. Customers planning for the future can deploy the 4200W power supply with a single 100V circuit. - Cisco Power Supplies