The STX Shaft Lock goes in the neck end of your shaft, where the head meets the handle, and locks them together in place, reducing rattle and keeping the head screwed on tight. 

• Proprietary STX technology to provide a more secure connection between the head and handle, reducing head rattle.
• Combination of inner core nylon and outer shell polymer to secure the screw, but minimize weight.
• Fits men's and women's 1" diameter shafts. The end of the shaft needs to be hollow. Note that many women's shafts are 7/8" diameter.