Polk Audio PB LC65i Rough-in Brackets for in-Wall Speakers, Compatible with Polk 620-RT, MC60, TC60i, LC60i, 90-RT and 900-LS, Adjustable Metal Arms & Wings, Easy to Install (Pair)
The brackets define the hole the drywall mechanic will cut out Pre-construction brackets are used to designate the location of the loudspeaker pre-construction brackets will make installing your inwall/in-ceiling speakers easier