This Water reservoir is self pressurizing and requires no power, pump or batteries. Simply fill by  connecting to a regular water outlet. The unit delivers high water pressure giving a well rinsed mouth and cleaning of periodontal pockets with the two attachments for the hand piece. One attachment gives a wide spear for washing out the mouth then a second attachment that gives a jet spray for cleaning perio-pockets and food packing The unit is a available in two sizes. Small (holding around 2.5 Gallons) and a large (around 5 gallons.) If you already have our Kelly’s irrigation hand piece it can simply be screwed onto this unit. ForPLEASE NOTE THE UNIT SHOULD NEVER BE LEFT FULL OVER NIGHT ESPECIALLY IN COLD WEATHER WHERE FREEZING CAN BURST THE UNIT.