The reservoir funnel is designed for one-directional use. The circular part goes into the water reservoir in the back of the WaterPik and the rectangle is supposed to fit onto the head of a sink. Although it is specially designed for my faucet head, you can use it by just holding it slightly below your faucet.
The two biggest spots on the one end of the "heads holder" are for the attachment that shoots water in a ray instead of a straight line and the one that shoots water straight but has a bristle on the end.
David S
