This is an original Craftsman replacement part manufactured for use with paint sprayers, tillers, spreaders, and yard vacuums. The special knob is commonly used as a wing nut, and its application can vary depending on the model of equipment. This knob is available as an individual replacement part, please see model diagram for part location and usage.
This is sold as a set that contains eight washers. These parts attach to the tank and are made out of metal. They are genuine items that are supplied by the original equipment manufacturer for use with Craftsman air compressors. During replacement, it may require a wrench to help install these parts correctly. They will require replacing if they become bent or broken.