Your search for "cfp-40g-sr4" revealed the following:
Cisco CFP-40G-SR4 40GB BASE-SR4 850nm MMF CFP Transceiver
SKU: NSH-3528
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 705.99
• Only 2 remaining
Call if you need more
Cisco WS-X6904-40G-2TXL 4x 40GB FC CFP Switch Module w/ DFC4XL
SKU: NSH-2146
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days
$ 557.99
• Only 1 remaining
Call if you need more
NEW Cisco CFP-40G-SR4 40GB BASE-SR4 850nm MMF CFP Transceiver
SKU: NSN-4233
Condition: New
Shipping: Overnight Options
Warranty: 365 days