0.20g Maruzen 4000 BBs.
These high quality BBs are manufactured by Maruzen in Japan. Maruzen is one of the oldest companies to produce BBs for the airsoft market are considered one of the original, high quality, standardized production BBs. Produced with a very high polish, they are recommended for all AEGs, gas-guns, and spring guns. The exacting standards involved in production make these perfect for use in high tolerance tightbore barrels.