Your search for "AP7750A" revealed the following:
For APC AP7721 AP7722 AP7750 AP7750A AP4423 ATS Ears Rack Mount Bracket Kit
SKU: NSB-6313
Condition: New
Shipping: Overnight Options
Warranty: 365 days
$ 24.99
• 247 in stock
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NEW APC AP7750A 120V 15A 8x NEMA 5-15R Rack Mount Automatic Transfer Switch
SKU: NSN-5842
Condition: New
Shipping: Overnight Options
Warranty: 365 days
APC AP7750A 120V 15A 8x NEMA 5-15R Rack Mount Automatic Transfer Switch
SKU: NSH-6212
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days