The PrimoChill Liquid Filling Bottle is a great tool for adding and removing fluid from your system. Filling the bottle with your desired coolant and then squeezing the bottle will allow you to control the amount of added coolant easily. This is a perfect technique for topping your system off. You can also remove the internal straw to use this for removing fluid. Squeezing the bottle will remove some air and act as a vacuum. This can be especially handy when trying to remove fluid pools from tight spaces.