Jacuzzi #6560-852 flow switch fits all J-310 and J-315 model hot tubs built from 2002 t0 2015
Also fits J-325 Model hot tubs built in 2004 and 2008 to 2015
If you have a FL1 error on your control panel, make sure the circulation pump is running and moving water before replacing the flow switch.
While this ships with a new 3/4" T housing, there really isn't any reason to replace the T. Carefully remove the old flow switch by unscrewing it and screwing the new switch in the existing housing.