Your search for "QSFP28-100G-LR4" revealed the following:
NEW Arista QSFP-100G-FR 100GB BASE-FR up to 2km over duplex SMF QSFP28
SKU: NSN-6740
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Juniper PTX10K-LC1101 PTX 10000 Series 30x 100G QSFP28 Router Line Card
SKU: NSH-9738
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days