The backbone travel cover support system is designed to protect golf clubs from direct and indirect impact that may occur while transporting clubs in a travel cover it is made from oversize and durable polypropylene top cap for maximum club protection and is lightweight aluminium tubing that wont add weight to your travel bag also has a precision lock spring loaded adjustment and rubber foot cap on the bottomsimple push button to adjust length 3 telescoping sections adjusts up to 136cm and