These "Self Weighted" Rubber Membrane Disc Diffusers provide a convenient and low-maintenance aeration solution for ponds. Thanks to their built-on weight, they remain securely in place at the bottom of the pond. They are suitable for use with air pumps between 3 LPMand 65 LPM. The MD-3W is designed to work with aquarium-style air pumps thanks to its 3/16" connector barb. It features a silicone rubber disc diffuser that is soft and easy to clean, offering very low back pressure and flow rates between 3 lpm and 5 LPM / 0.1 cfm to 0.2 cfm, making it ideal for small ponds or aquariums (0.4-pound weight). The MD-5W and MD-7W have a 3/8" connector barb for larger air pumps. They feature an EPDM rubber disc diffuser that is easy to clean, offering very low back pressure with the following flow rates: - MD-5W: 8 LPM- 35 LPM/ 0.3 cfm - 1.2 cfm (1.75-pound weight) - MD-7W: 15 LPM - 65 LPM/ 0.5 cfm - 2.3 cfm (3.3-pound weight). Both are great choices for smaller ponds! SPECIFICATIONS MD-5W MD-7W Disc Body PP+Lead Membrane EPDM Connection 3 / 8" 3 / 8" Dimensions: Dia.(in) / (mm) 5 / 130 7 / 180 Weight (lbs) / (g) 2.36 / 1070 3.32 / 1504
