From the back of the book:
When corpsec is raining lead down on your head, a wardrobe malfunction will get you dead. To survive against gangs, syndicates, and megacorps, shadowrunners need the best gear they can make, buy, or steal. Arsenal covers everything a runner team needs, from weapons and armor to advanced electronics and spy toys to the latest state-of-the-art drones. It also covers the intricacies of the black market and drug trade and provides advanced rules for combat and martial arts, mixing your own chemicals and explosives, and modifying your weapons and vehicles.