(4) pieces Control & SAVE on energy bills with registers that let you control every room’s airflow with their infinitely adjustable louver assembly (damper box). Crafted of solid steel these registers are stamped from 9 guage steel. Mounts to floors or ceilings, damper box cannot be locked in place. The protective RSF baked-on powder coating provides a luxurious matte finish, their traditional scroll design & heavy steel are of superior quality workmanship. Mounting hardware included. Overall 3 1/2 x 13 1/8.