1/pk Reusable organic cotton coffee filter made to fit 64 ounce canning jar or similar - CoffeeSock ColdBrew filters are durable and may last a year or more. CoffeeSock ColdBrew filters are a reusable alternative to paper filters and nylon sacks. All of our filters out-perform any comparable disposable and reusable filters. Cotton absorbs some of the oils released from coffee beans yet lets acids pass through.