... features as follow,A, Auto Initial Height Sensing(IHS)Torch Retaining Cap IHS and Proximity Switch IHS, Proximity Switch IHS is backup ... for Torch Retaining Cap IHS for cutting dirty/rusty workpiece, needing the Anti-Collision ... THC, XPTHC-300, and CHC-200E.2012 designed DC version cap THC for Zinser, and new laser CHC-300.