Blackjack is a hybrid strain that was created by crossing Black Domina with the legendary Jack Herer strain. Blackjack gives a very relaxing and long lasting high due to its high potency levels. Good for stress, pain, and headaches. All the flavor of the flower comes through into the cartridges. they are the same price as the O.pen originals but double the potency. our best valued cartridge. Tested at 78.9% THC