The SCPEN4 Series feature a whistle cap, ferro rod and strike plate. The threaded pen cap has a built-in emergency whistle along with a pocket clip. The ferro rod is accessed by unscrewing the butt end of the pen. Lastly, the striking plate is accessed by unscrewing (reverse-threaded) the breaker tip, which can then be threaded back on to the butt end for use as a handle. The SCPEN4 makes an excellent addition to your daily carry and survival gear.