@piaakit I am using one EAP610 Outdoor with four EAP225 Outdoor. Yes they will work in Mesh mode. You will need a controller but it does not have to be the hardware controller. You can use the Windows Software Controller at no cost. If you want to use the Cloud Controller you need to buy licenses. If you choose one of their hardware controllers, like the OC200 I am using, then there is no licenses needed for Cloud Control and you also have local control.

How may APs are you planning on having and why are you seeking Mesh?  Mesh sounded interesting to me but I have found that in my scenario, which is an RV Park with around 25 total connected devices, its not that appealing. The loss of speed is the main issue since we have 300 down and 32 up but cannot deliver all of that. We are getting Gigabit Service in 8 days so going to have to come up with a different solution to try and pipe more of the bandwidth to our guests.

  @RickJamesBish we are planning to use 1 x eap610 and 1 x eap225, there are only a few equipment need to connect with the wifi only, it has the constraints to lay a pipe with network cable to connect AP in other side, so we designed to use mesh to increase the coverage 

  @piaakit You could probably just use two EAP225.