It's suitable for 21mm - 25mm bottle neck,such as Mineral water bottle, Soda water bottle, Coca-cola bottle, Pepsi Cola bottle etc. People only need to buy our bidet sprayer head, no need bottle body. Simply find a water bottle and fill with the water, screw on the portable bidet, point the ergonomic nozzle in the correct direction, and squeeze the bottle to get a cleansing. Our portable bidet is very friendly to adult, children,elder,patients and new mother recovering from postpartum/surgery. Add warm water or saline to the bottle.