Hi @cisco_Meraki,
If you are looking for additional clips for mounting the access point to the rails in a drop-in ceiling, I believe the SKU is MA-MNT-CLG-1.
If you are looking for the flat mounting cradle that ships with the AP, you might contact sales to see if that's available to be ordered.
https://meraki.cisco.com/form/contact
Found this helpful? Give me some Kudos! (click on the little up-arrow below) and If my reply solved your issue, please mark it as a solution 🙂