Arguably better than Heavy Hitters, these Eureka Clear cartridges are filled with 1000mg of 100% natural, solvent and additive free CO2 extracted cannabis oil that test around 90 to 95% THC. These cartridges are compatible with 510 thread batteries. Awarded for best CO2 Concentrate at the Hempcon Cup 2015. Fast and Friendly offers 24hr 100% replacement for any factory defects, Replacement is for product to same product received. NO cash back, NO instant credit. Fast and Friendly does NOT replace EMPTY oil cartridges or cartridges that have malfunctioned due to patient error/mistreatment.