Size: 3.2" - 0.3 cfm
These diffusers are made from fused alumina. They produce a bubble size of 1.0 to 2.0 mm and require a higher pressure than a medium pore diffusers. They have a molded square rubber support on each end that supports and protects them from tank bottoms and protects the tank or liner from the diffuser. They fit both 3/16” and 1/4” tubing and are 1.2” diameter.