OrionPower OFC-3R Propylene-Butane High Pressure Gas Fuel Cell for Cordless Gas Nailers (Small Size 78 mm) (2 Pack) For use with Paslode IM250/65 and Hitachi Brad Nailers High pressure Propylene+Butane innovative blend delivers plenty of power for all applications Two 3-inch (78mm) fuel cells per package. Best Use By Date: Jan 15 2016, Buy one and get one free Each cell contains enough fuel to fire 1000 nails Ready to use when cap is clicked in place front to back