Use pre-construction brackets when installing ceiling speakers. The snap-away Wings make it easy to mount your speaker first to the bracket itself, then between the stud made from ABS, this bracket works perfectly with joists Spanning 12. 5" To 29. 0". This bracket is designed to fit most round 6. 5" Installed speakers. features: use the adjustable arms to attach the bracket to stud or joists before The drywall goes up> the arms are adjustable to allow for unusual stud or joist locations> It can be attached using nails, dry-wall screws, or construction staples (not included> Solid ABS pre-construction bracket> fits between joists 12. 5" 29. 0" Apart> snap-away Wings make installation simple