Purpose: Making the 4 litre / 135 oz. sizes more easy to use, these pumps are spring loaded and constructed out of high density HDPE to ensure they last. They can be reused after you have finished your 4 litre unit and just need a quick clean! No need to buy another pump for every order.   
 
To Use: Simply replace the stock cap with the pump and get pumping. 

NOTE: This pump is for the 4 litre units ONLY and will not fit any other unit size.