The Haakaa Generation 3 Breast Pump comes in two convenient sizes of 160ml and 250ml and is compatible with all of the Generation 3 bottle range attachments.( Sold Separately) The Haakaa Breast Pump is great for long-distance trips, planes, car rides, family BBQsor anywhere you would like to express silently and quickly. just place it over your breast and let the pump do the work for you as it draws your milk using suction. How to use your Haakaa Breast Pump : 1) Sterilise your pump using the directions provided 2) Place the pump flange over your nipple - make sure your nipple is centered comfortably in the neck of the pump. 3) Apply suction - you may need to adjust the position of your pump a couple of times. once the pump is secure and comfortable, apply suction by squeezing the base of the pump to start the flow of milk. 4) Once milk begins to flow, simply leave the pump alone to do its thing 5) When the pump is full or session complete apply a twist of the top and you can swap out your breast pump flange for any of the range of optional interchangeable attachments (Sold Separately). Tips: encourage let-down by placing a warm flannel on top of your breast and massage gently. While your child is feeding, attach your Haakaa pump to the other breast to catch precious milk that would otherwise be lost in a nursing pad.