Premium Extension Gauge This handy little tool takes all the guesswork out of choosing the correct graphite or steel extension. Simply insert the Premium Extension Gauge into the butt end of the shaft needing an. extension and match the color code with the butt extension color. Eliminates the need for excessive sanding or build up tape to fit those larger and smaller butt diameters that club makers are constantly encountering. Note: The correct color dot is inside the golf shaft just below the next visible colored dot outside of the shaft butt. “For our valued international customers, please be aware that all customs-related responsibilities are the customer’s responsibility.”