Body armor contains material that disperses the energy of a fired bullet throughout the armor, such that the bullet lacks sufficient force to penetrate the thickness of the armor. There are two types of high-strength fibers used in bullet-resistant panels for soft body armor: high-performance polyethylene fibers (HPPE) and aramid fibers. Among the top fiber makers, Honeywell's Spectra and DSM's Dyneema are HPPE fibers. DuPont's Kevlar and Teijin Twaron's Twaron are aramid fibers. Each type of ballistics material has its own properties, and each type is better at one function than the other. For this reason, some companies make hybrid vests, which use a variety of materials to provide the most effective and comfortable vest for general police work. Some companies have made a special effort to design and construct body armor for policewomen. Savvy Armor is a new, stand-alone, all-female company dedicated to manufacturing safe and comfortable armor for women. Savvy uses different technology in the measuring process for designing women's armor compared to that used in designing body armor for men. Savvy uses only soft woven aramid fabric that forms better to curves than other materials. The weave also increases the breathability in the vest, adding to comfort.