Arlington’s all-metal fixture box is a one-piece assembly that ships ready to install on a 24" suspended ceiling grid – No assembly required. It’s tested and rated to support exit lights, security cameras, smoke and carbon monoxide detectors – and light fixtures up to 50 lbs.No more guesswork. Installers who previously attached a metal box to a bracket in the field then added a chain or wire for support, now have an assembly that is fully tested to hold up to 50 lbs! FS420SCL is UL/CSA Listed as a complete unit: box, bracket and drop wire.