SPIN cables allow your tips to swivel freely! They are made of pliable, clear nylon. As an example of how the lengths work, an 8″ (20 cm) length can be used with our 4″ (10 cm) TWIST tips to make a 16″ (40 cm) circular. Lifeline holes can be found at each end of these cables. Insert the T-shaped tightening key into the lifeline hole to assist with securing your tip/cable connection.