The Valken Accelerate ProMatch 0.40g airsoft BBs are manufactured in Taiwan by one of the best-known Airsoft BB manufacturers. These 6mm plastic airsoft BBs are precision grade quality, completely spherical, contain less than 5% air bubbles, and are polished multiple times throughout the production process to ensure that the BB is seamless and has no surface imperfections. These 6mm precision BBs give you greater accuracy and consistency. They are packaged in a unique rectangular bottle with a screw-on cap making storage, transport, and loading simple and convenient. Accelerate BB bottles do not roll around like other round bottles, which can spill easily. We recommend our Valken M4 Magazine Style BB Speed Loader for use with Accelerate BBs when loading mid-cap magazines.