One outer sleeve for the JoPo install Does NOT contain inner sleeve Benefits of the Twist: The thread-like feature absorbs the load of the weight and the velocity of the bowling ball delivery; i.e. visualize pulling a nut straight off a bolt without unscrewing it. The Twist cannot be removed from the bowling ball without the inner being rotated 360 degrees Easy to install and superior quality compared to other systems Length: 2 3/4 Hardness: 75