Hi plonetti,
When the AP4051DN functions as a Fit AP, it can be managed by the AC6005.
The AC6005 can manage a maximum of 32 APs under license control.
The version mapping between the two parties is as follows:
AP-------------------------------------AC
V200R007C20----------------V200R007C20
V200R008C00----------------V200R008C00
V200R008C10----------------V200R008C10
V200R009C00----------------V200R009C00\V200R010C00\V200R019C00\V200R019C10
V200R010C00----------------V200R010C00\V200R019C00\V200R019C10\V200R020C00\V200R020C10
V200R019C00----------------V200R019C00\V200R019C10\V200R020C00\V200R020C10\V200R021C00
I hope it helps!