Your search for "ma-ant-20" revealed the following:
NEW Cisco Meraki MA-MNT-MR-16 Mounting Kit for MR76 MR86 Access Point
SKU: NSB-3803
Condition: New
Shipping: Overnight Options
Warranty: 365 days
Cisco Meraki ANT-10 5/7 dBi Dual Band Omni Antenna
SKU: NSB-3582
Condition: Seller refurbished
Shipping: Overnight Options
Warranty: 365 days