The AquaFX Double 20X4 Canister Bracket is a heavy-duty steel mounting solution specifically engineered to securely hold two 4x20 canisters for your saltwater aquarium's RO/DI system. This bracket provides essential stability and organization for the vital water purification components of your reef setup, ensuring they are safely and neatly housed. This robust bracket is constructed entirely from durable steel, designed to withstand the demanding conditions of an aquatic environment. It is precisely sized to accommodate two canisters that measure approximately 4 inches in diameter by 20 inches in height. It is important to note that the "4X20" designation refers to the internal filter size, but the bracket is made to fit the external dimensions of these larger canisters, which are typically utilized in commercial-grade RO/DI systems such as the AquaFX Blue Marlin. This double canister bracket is an excellent choice for dedicated reef aquarists and hobbyists who employ larger, high-capacity RO/DI systems and need a reliable, long-term mounting solution for their filtration units. It offers peace of mind by ensuring your critical water purification equipment is securely supported, which is fundamental for achieving and maintaining the pristine water quality necessary for a thriving reef aquarium.