The Pelican Pump fits the 2.7 Litre, 5.7 Litre jugs from K9 Competition.

It comes with the top pump and insert hose. 

you CAN modify your current pumps if needed to fit K9 by drilling a hole through the "cap" of the k9 lid and replacing the cap on your current pump with it. Might not work with all makes of pumps.