Made of virtually unbreakable plastic, the SD can increase the ability of the average person to defend himself several times over. With proper training, it can function as a fantastic aid in leverage when obtaining joint locks or submission holds. But where it really shines is as an intermediate impact tool. You see, police and civilians alike face a perplexing dilemma when contemplating employing fist or baton blows. Blows struck with the fist may be too weak, or worse, result in a broken hand, while blows struck with a baton may be too powerful resulting in grave injury or even death. The SD1 however, solves this problem, neatly bridging the gap by concentrating and magnifying the effect of hand blows while minimizing the likelihood of permanent injury or death. If you're looking to expand your continuum of force options in a self-defense situation, Cold Steel heartily suggests you buy a Koga SD2.