Callaway Steelhead Pro Series X-14 Callaway Steelhead Pro X-14 Shaft: Rifle Flex: R A legendary club, even Mr. Mark Kanai couldn't resist buying it on impulse. The legendary Callaway Steelhead X-14 PRO SERIES, a set of 8 irons. Normal series also available, can be used as combo irons. I used the Pro Series for the short irons, and the normal series with a goose neck for the middle and long irons. It's the best. Please feel free to inquire about set sales.