The top-of-the-line Return Air Grille is bar type. The best bar type Return Air Grille is made of aluminum. Light weight, rust resistant and durable, TRUaire A270 Return Air Grille is the best of the best for residential return air applications. Each aluminum fixed blade is set at 45 degrees and 3/4" apart. Finished in pristine white powder coat, this is a tough act to follow.