The EAP300 cannot be mounted on a T-rail and can only be mounted on the
ceiling via the proprietary mounting kit that came with it in the box.
If using a T-rail mount is a requirement, consider installing the EAP600
instead as it does come with two (2) sets of T-rail connectors of
different sizes, the 2.38cm and the 1.43cm T-rails.
Figure 1: EAP300 with proprietary ceiling mount.
Figure 2: EAP600 with T-rail mounts