• This Double Membrane Air Diffuser assembly features a hollow base that can be filled with sand or gravel
• Eliminates the need for bricks and straps to get the diffuser to sink!
• 3/4″ female threaded outlet located in the base of each diffuser
• Available in a single, double or quad head assemblies
• Single head handles airflow from .8 – 3 cfm , double head handles airflow from 1.6 – 6 cfm and quad heads handle 3.2 -12 cfm.