Bridgestone’s proprietary new Active Acceleration Mantle layer is a key component of the 3-piece construction. The Active Acceleration Mantle is comprised of a new High-Performance Polymer material that provides increased thrust and higher initial velocity at impact while allowing Bridgestone to soften the core for greater forgiveness and enhanced feel — designed specifically for players with less than 105 MPH driver swing speeds. The e12 SOFT utilizes Bridgestone’s Delta Wing Dimple pattern for less drag and optimized aerodynamics in the cover.