Commercial Electric 81745 is a 4in Offset Swivel Crossbar designed to help you securely mount lighting fixtures. It has a 35 lb load rating and does not include hardware which you need to securely mount a lighting fixture. To use the crossbar, first turn off the power supply before installation. Then, thread the fixture screws (not included) through the crossbar towards the light fixture and align them with the holes of the fixture to be mounted. Position the flat side of the crossbar against the electrical box and secure it using two (2) crossbar screws.