The 24”x24” PLQLT has a square faceplate made of one-piece, non-folded material with rounded corners, backed by 3/8” thick cellular liner that insulates the plaque from cold supply air. Held in place by hooks that lock into the backpan, the single faceplate gives the diffuser reduced pressure drops and a quiet sound profile. The one-piece stamped backpan provides smooth, consistent corners, exacting dimensions, and performance tolerances and is covered with a foil faced R-6 formed fiberglass backing to provide excellent condensation resistance. Additionally, the removable faceplate offers easy duct and damper access.