This is an original manufacturer-sourced part which is designed for Graco sprayers. The base helps to secure the drain valve. If it is missing or is damaged, it will provide an identical replacement for the original component that was installed on a new unit. Refer to the owner's manual and the appropriate diagrams for the correct applica...Read moretion and replacement procedure. Note, this high-quality valve base is made of a durable plastic and is sold individually.