Simply drop this lightweight 2.8oz Rumble Go filter into a compatible water bottle, and you've instantly transformed it into a portable cold brew coffee maker. The brewing process couldn't be easier: just add Yellow Dog coffee grounds to the filter and water to the bottle, then seal it up and give it a "rumble" (i.e. rotate bottle horizontally 2 times), and your coffee is now brewing! By morning, you'll have cold brew coffee almost as good as Rob makes!
Fits inside most 16-32oz. wide mouth water bottles.