Fill the filter with coarse ground coffee, pour hot water over it into the bottle, cap the bottle, invert the bottle and wait a few minutes for the coffee to brew. Then unscrew the H2JO, dispose of the grounds and drink the coffee. I liked this method best because it made cleanup very easy and the H2Jo doesn&';t leak; it&';s very well made. Features: It&';s simple just fill your bottle with hot water, screw on the filter, add grounds, close the lid and let the magic happen You can also choose to make "cowboy coffee" by added grounds directly to water, then screw the filter on and pour water into a mug Filter effectively keeps grounds out of your coffee GSI H2jO! coffee filter fits wide-mouth water bottles with 63mm openings. Does not fit on Innate or Klean Kanteen stainless-steel wide-mouth bottles