This product is either discontinued or we cannot get that from suppliers.
Cisco WS-C4500X-40X-ES Catalyst 4500-x 40 Port, Expansion Slots 40, Management Port 10/100/1000 Base-T, USB Port Type A (storage and boot) up-to 4 GB, System Throughput Up to 800 Gbps, Port Buffers 32-MB Shared Memory, Dual Core 1.5 GHz.
WS-C4500X-40X-ES is one of the Catalyst 4500-X series switches. The Catalyst 4500-X series switch is a fixed aggregation switch that delivers best-in-class scalability, simplified network virtualization, and integrated network services.