Rectangular Vent Grill, Fits 2-1/2'' x 10'' Opening - Rockler
Engera Bathroom Door Air Vent Grille Two Sided Ventilation Cover for Restroom, Warehouse, Storage Doors | Interior Door Transfer Grill 453mm x 91mm (18.1"x3.6") - - Amazon.com
Linear Return Air Grille | Air Vent Covers | Vent Covers
Accord Ventilation 16-in x 16-in Louvered Sidewall/Ceiling in White at Lowes.com