SMI Ventilation Products is your source for decorative registers and grilles. At SMI Ventilation Products, we introduce, design, manufacture and distribute the latest unique plastic grilles that will enhance the beauty of your home. Our grilles are injection-molded, high-impact polystyrene (HIPS). Our grilles are finished white and can be painted to match the interior of your home. We currently have 15 grilles to offer. Refer to the product chart for available sizes.