T5 adapter is for updating T8,T10,T12 fluorescent lamp to T5.Easyfit T5 adapter saves both energy and installation costs. T5consumes only a  fraction of the energy required by thetraditionalt8, t10 and t12 tubes while maintaining the same brightness, moreover, with the electronic ballast in  the adapter, the replacementwill give more than 30% energy saved. And it's installable on existing T8/10/12lamp frame, the installation is the same way as replacement of a burnt tube. Allyou need to do is to replace the old tube and starter by the adapter with T5 tube and new starter. it's all.