Your search for "en-slx-9640" revealed the following:

Extreme EN-SLX-9640-24S 24x 10G SFP+ 4x 100G QSFP28 No Fans No PSU Switch

SKU: NSH-8533
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days

Extreme EN-SLX-9640-24S-AC-F 24x 10GB SFP+ 4x 100GB QSFP28 F-B Airflow Switch

SKU: NSH-8534
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days