i have some super fine caps machined with precision that also allow for a lanyard to be attachd in the center groove so ya don't loose it. i was concerned with dust and debris getting into the hose/gauge assy on the foster quick connect. so this cap will look great on your foster fitting for bottles and pumps. in the field dust is every where. in a garauge, metal and dust are present. the pump hoses are so close to the ground that dust can migrate into the cylinder and then into the firing valve area which can cause damage. this cap will greatly reduce or illuminate that chance.
100 percent made in the USA
916 752 6762