Superior performing Culligan compatible TFC 50 gallons per day reverse osmosis membrane that is excellent for the LC-50 and the AC-50 drinking water systems. Can be used in place of part # 00-4015-33, TFM-50-A, 1224437, 01-0060-98, and others. Made in the USA. NSF certified. We also carry all of the filters for each RO model.