I need to add wireless to a clients home network, they are on point-to-point wireless for their connection, and already have a router installed that's pre-configured for their setup with PoE to power the antenna on the roof

I have been asked to add wireless to their setup, am I right in thinking I'll just need an Access Point, something like this:
http://www.tp-link.com/en/products/details/?model=TL-WA901ND

Cheers