QMP Inc.’s high-pressure housings are made from the highest quality reinforced polypropylene. Designed to be chemical resistant, Slim Boy and Grande Boy exceed industry standards and are proudly manufactured in the USA. The QMP400-20BK housing holds one standard 20” L x 4.5” W (50 x 11-cm) water filter cartridge. The QMP400-2025 housing holds one standard 20″ L x 2.5-inch W (50 x 6-cm) water filter cartridge. Both are ideal for a wide range of applications, including residential, commercial and industrial uses.