This manual drinking water pump is like no other.This model will fit onto any size bottle, screw-top or crown-top except glass bottles and Primo brand bottles.It will have no problems fitting and pumping water from 7.6l through 7.6l water bottles.The new fastener system can grab onto and seal any bottle is a breeze.The new fastener was designed with hygiene in mind.Previous models have always had a bunch of ridges and rough areas that are safe havens for germs.The new design has all of these parts on the inside with a nice surface on the outside.Simply adjust your tubes according to the size of the bottle and tighten the pump onto the bottle.This pump will dispense water as fast as you can pump it and it will do it very well.