Our box of ten 8g CO2 cartridges are custom fit for the Byrna HD. Now including 1 CO2 cartridge with oil for simple maintenance every 10 CO2 cartridges used. Each cartridge (new) will be good for 15-20 rounds (4 mags in a 5 round magazine) at full speed. Punctured cartridges within the Byrna HD will leak over time. It is recommended to swap out punctured CO2 cartridges and leave an un-punctured cartridge inside the Byrna HD to avoid any compressed air loss. The Byrna HD will puncture and fire the first round at the same time.

CAPACITY: Each CO2 cartridge will be good for 15-20 rounds. EASY TO USE: Simply install the oiler cartridge like any other 8g CO2 cartridge and fire away! The CO2 with Oil cartridge does all the work while you fire. WHAT'S IN THE BOX: (10 ct.) 8g CO2 Cartridges. Including 9 standard 8g CO2 cartridges and 1 CO2 cartridge including oil for maintenance.

Cross section shape: Round. Pattern: Solid. Shape: Round. Style: Classic. Brand: Byrna. Date First Available: June 8, 2021. Best Sellers Rank: #33,116 in Sports & Outdoors. Customer Reviews: 4.6 out of 5 stars 435 ratings 4.6 out of 5 stars. : B08Y79HQTK. Style: ?Classic. Brand Name: ?Byrna. Package Weight: ?0.32 Kilograms. Item Package Dimensions L x W x H: ?4.37 x 2.83 x 1.65 inches.