Heavy Hitters currently have the biggest cartridge on the market weighing in at 2.2 grams of CO2 distillate THC oil. The strength of Heavy Hitters cartridges vary. Some of their strains test as low as 71% THC while others like their blue dream 2.2-gram cart lab tested at 95% THC. I personally tried their 2.2-gram cartridge of Bubba that tested at 87% and was impressed with its strength. It was definitely at the same strength level as Brass knuckles cartridges which test as high as 90%. The official website for Heavy Hitters is heavyhitters.co.