Barrels offer the next step up in stability above the Cones and are often used for a broad range of skating disciplines depending on the skaters skill level and personal preference. 

APS™ Formula:  Animated Polymer System

As the name implies, this compound is very lively and offers high rebound with lots of control and lean.  For the same durometer, the APS will turn 10% to 15% more than the same durometer of other brands.  In addition, the APS does not change much when you tighten the kingpin nut past snug.  We recommend tightening to the point where it is difficult to turn the bushing in the bushing seat by hand.  Use a flat washer for lower resistance and a cupped washer for higher resistance.