Airsoft is a hobby or sport which uses replica firearms to shoot small plastic pellets around six millimeters in diameter. Common uses for airsoft are competitive gaming (similar to paintball), military simulations, target shooting, and military training. While similar in operation to BB guns, airsoft guns use lightweight (usually) plastic projectiles (BBs) 6mm in diameter instead of metallic 4,5mm BBs. Airsoft guns also typically have a muzzle velocity of less than 180 m/s (600 ft/s), compared to a BB gun which may have a muzzle velocity of 365 m/s (1200 ft/s) or more. The combination of the lighter BB projectile and the reduced muzzle velocity means that airsoft is generally considered safe when used in a controlled environment and with safety equipment like protective eyewear.