For your consideration, here is a United Airlines Ask Me About Mileage Plus For Frequent Flyers Advertising Pinback Button, Pin.  It has some wear, nicks and is scraped on the left edge.  There is some tarnish on the back.  The button has a diameter of 3 inches.  Item pictured is the actual item up for sale and comes from a non-smoking household.  (570.17u-.3px2)