Arlington new economical T-Box™ is the cost-effective way to mount a fan or fixture on a suspended ceiling grid. What's neat about this T-Box™. It can be positioned on the ceiling grid at the cross of the T-rails - or on the straight away so you decide where you want the fan/fixture!. Uses include fans and fixtures of course, but also smoke and carbon monoxide detectors, security cameras, exit signs and emergency lighting. and they're easy to install! simply cut around the ceiling tile. Then lower the box into place onto the ceiling grid where it's held securely in place. For use on premium/reveal edge ceiling tiles, the box height adjusts by removing the tabs with pliers. Easy and convenient!.