FITS CROWN TOP & SCREW TOP JUGS — This 5 gallon water jug pump sits directly on 55 mm crown and snap top jugs — no adapter needed. For screw-top bottles, use the included 53 mm adapter. COMPLETE WATER JUG DISPENSER KIT — A ready-to-use water bottle pump set: 3 connectable tubes for any bottle height, a sanitary dust-cover for the spout, the 53mm adapter, and a flexible brush.