Your search for "QSFP-40G-LR4" revealed the following:

NEW Arista QSFP-40G-LR4 BASE-LR4 40GB 1310nm Long Reach SMF LC QSFP+ Transceiver

SKU: NSN-8262
Condition: New
Shipping: Overnight Options
Warranty: 365 days

Juniper SRX-QSFP-40G-LR4 40GB BASE-LR4 850nm MMF QSFP+ Transceiver

SKU: NSB-4608
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Cisco Meraki MA-QSFP-40G-LR4 40GB BASE-LR4 1310nm SMF QSFP+ Transceiver

SKU: NSB-0838
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Dell QSFP-40G-PSM4-LR 2XJHY 40GB BASE-LR4 1310nm SMF 2XJHY QSFP+ Transceiver

SKU: NSN-0835
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

NEW Brocade 40G-QSFP-LR4 40GB BASE-LR4 1310nm SMF DDM SC QSFP+ Transceiver

SKU: NSN-3763
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Juniper JNP-QSFP-40GE-IR4 40GB BASE-LR4 1310nm SMF LC QSFP+ Transceiver

SKU: NSN-5340
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Juniper JNP-QSFP-4X10GE-IR 40GB BASE-LR4 1310nm SMF QSFP+ Transceiver

SKU: NSN-6362
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW HPE JG661A 40GB BASE-LR4 1310nm SMF LC QSFP+ Transceiver

SKU: NSN-5570
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW Nvidia Mellanox MC2210511-LR4 40GB BASE-LR4 1310nm SMF LC QSFP+ Transceiver

SKU: NSN-8602
Condition: New
Shipping: Overnight Options
Warranty: 365 days

NEW HPE JH232A 40GB BASE-LR4 LC SM QSFP+ Transceiver

SKU: NSN-4251
Condition: New
Shipping: Overnight Options
Warranty: 365 days