Simply twist the Pet Top® drinking device onto one of the many compatible water bottles, by gripping the base of the unit and turning clockwise onto the bottle neck until it fits snugly. Hold the base of the device and turn the upper cap counterclockwise to the open position that’s best for your pet. Indicator markings help you easily remember the desired open position and ratchet-action keeps the device open at the desired setting. The Pet Top® drinking device is designed to be used by pets of various sizes—to minimize drips and prevent your pet from taking in water too fast, please use the smallest opening that works for your pet and do not squeeze the bottle.