The Arc ST has undergone some changes. The Arc s lightweight frame, comfortable medium flex straps and highbacks turn this binding into one of the best splitboardbindings for trees and powder. The design is simple and durable which is nice when circumstances get difficult. ST stands for smooth touring where friction and wear are eliminated. The whammy bar (heel riser) is connected to the binding and ensures that the crampons are always fully engaged. The addition of the skipole adjustable heel riser makes this one of the most practical bindings in the field. The perfect binding for any splitboarder heading for the backcountry.