Satisfaction with them depends on the distance between ceiling joists. The ceiling joists in my case were trusses spaced 24 inches apart. The design would be acceptable if you wanted a center box, but if you need to press it against the truss for a basic room configuration, they are too short for a stable installation. Additional washers must be fitted to reduce the gap. IMO, even after I installed the box supports were pretty flimsy. I ended up drilling a hole through one side of the supports…