Abstract: The invention relates to an improved water pipe and water pipe accessories for the smoking of smokable substances such as tobacco, herbs including medicinal herbs, and other substances suitable for such activity. Various cap designs disclosed herein provide an improved system for inhalation from any of a variety of water pipes. Instead of applying a person's mouth directly to the water pipe, the person uses the cap or mouthpiece. The addition of features to the cap or mouthpiece allows for new ways of cooling, adding flavor, and filtering all in one cap structure that is removably fitted onto the water pipe. This mouthpiece is suitable for personal use, is more hygienic, has improved ergonomics, improved cleanliness, improved suction, and may be interchangeable on a water pipe with other mouthpieces. The mouthpiece designs can be designed for long term use, or for short term use and be disposable.