This funnel has a one quart capacity, you need to add 2.2 qts to refill the differential. The funnel also has a valve at the base (blue part) that you can open once you've filled the funnel. The hose has an outside diameter of 3/4". I replace the hose that came with the funnel because it was a little short and I didn't want it coming out of the fill hole with the when I opened the valve. Having the valve allows you to have both hand available, one to secure the hose, the other to open the valve.