Airsoft pellets are spherical projectiles used by airsoft guns. Typically made of plastic, they usually measure around 6 mm (0.24 in) in diameter (though selective models use 8 mm), and weigh 0.12–0.40 g (1.9–6.2 gr), with the most common weights being 0.12 g and 0.20 g, while 0.25 g, 0.28 g, 0.30 g and 0.40 g pellets are also commonplace. Though frequently referred to as “BBs” among airsoft users, these pellets are not the same as either of the 4.5 mm metal projectiles that BB guns fire, or the 4.6 mm (0.180 in)-sized birdshot from which the term “BB” originated.