For use in Spring, Gas and Electric airsoft guns. 6mm biodegradable airsoft BBs Highly polished 0.20g 5000 rds White We use only 100% eco-friendly, biodegradable materials for our bio BBs. It takes approx. 11 months for these BBs to degrade once exposed to the elements (rain, snow, etc.). BB Diameter: 5.930 + 0.025mm Mean mm 5.928 Min. mm 5.907 - Max. mm 5.947 For precision airsoft use only! 6mm