Tru Aire steel registers, grilles and diffusers in white and brown powder coat: 2-way and 3-way floor registers, wall and ceiling registers, baseboard diffusers and return air grilles. The size printed on a register is the duct opening it fits, not the outside dimension of the faceplate, so a 4 x 10 register goes in a 4 x 10 boot and covers more than that. Supply and return are different parts — a supply register has an adjustable damper and directional vanes, a return grille is fixed and open, and putting a damper on a return chokes the system. Two-way and three-way describes how many directions the vanes throw, which is what you use to keep air off a wall or a seating area.
