you tap the spatula on the side of the bottle, to build up the pressure. then you swing the spatula up and dlip the side of the cap and it flies about ten or fifteen feet in the air... anyway, i was using a BBQ spatula that has the one edge like a steak knife. instead of catching the side of the cap, it went right into my thumb... very funny, what a bleeder. Went to the hospital the next day for 4 zippers.