Compatible 802.11ac Adapters
The WiFi Pineapple Mark VII supports 802.11ac monitor and frame injection with a supported adaptor.
The WiFi Pineapple Enterprise comes equipped with 3 MT7612U 802.11ac capable radios, but you may add more via USB if desired.
Adaptor
Chipset
MT7612U
AWUS036ACM
MT7612U
EP-AC1605 V1 (V2 is incompatible)
MT7612U

Installing drivers for other WiFi Adaptors

While the WiFi Pineapple has support for MT7612U and MT7601U devices out of the box, you can also install drivers for a wide range of other chipsets, such as other MT76-based devices, ath9k and ath10k devices, and some Realtek dongles.
To find drivers, you can use the Package Manager found in the Web Interface under Modules > Packages. Search for keywords related to the chipset in your adaptor.
More information about your specific adaptor can usually found with resources such as WikiDevi.