Vacuum Exhaust Mufflers Porous Plastic Mufflers Model No. M-14/30 ANVER Part Number Exact Replacement For P-Series Muffler No. AThread NPT BDiameter in. (mm) CLength in. (mm) Filter Size Microns Weight oz. (g) M-14/30 N250FF 1/4″ 0.66 (16.8) 1.40 (35.6) 30 0.10 (2.84)