Pre-construction in-ceiling Speaker Brackets are unique. Made from durable plastic, they employ shatter-resistant, flexible and strong aluminum wings with an integrated EZ-Alignment slot. This slot enables the bracket to be moved (slid back and forth), similar to a recessed light, for perfect alignment. These brackets also employ speaker wire retention clips, providing a safe environment for the speaker wire during rough-in and dry wall installation. They also accommodate 16" and 24" on-center installations. Sold in sets of two.