Havaco's Plastic 2'x2' Supply Grille is Made in the USA from premix white ABS polymer. It won't rust, fade, or chip. The Havaco Supply Grille can also be used as a Return and features our patented easy attach knob for simple removal of just the grille face for fast efficient cleanability. The Supply Grille back has a pre-molded boot available. he Havaco Plastic Supply Grille is available now and is 157 times less conductive than metal and the pre-molded register boot inlet is 2" high and features several retention points to easily attach flex duct.