Mikrotik Woobm-USB

The Wireless out of band management USB stick (Woobm-USB) is a useful assistant for any network administrator. Simply plug it into any RouterBOARD USB port and it will allow you to access the console of that device over wireless. It sets up as a wireless access point and has a simple web interface where you can access a fully featured terminal interface to configure your router, and where you can configure the Woobm itself.

It can even work as a wireless client: if you wish to manage many devices, just connect all the Woobms to one AP inside your server room and manage the routers through there.