The freehand blast, also known as the gravity blast, utilizes the gravity roll technique in a blast beat context. Of all the main blast beat variations, this one is the most recent to have emerged. The snare line is played as a 16th notes single stroke roll, also known as a gravity roll or single handed roll. The roll is played with an up and down motion in which you push and pull the drumstick on and off the snare drum. By using the snare rim as a fulcrum you create a stroke each time you push and pull the drumstick up and down. In this way, the player can double the output of notes to match the amount of notes produced by two feet on the bass drum. It usually presents similarly to a unison hammer blast, but at double the tempo of what would be possible with normal techniques. One drawback is that this blast has a limited volume. The concept behind the gravity roll is not new, but is noted for being brought into modern music by drummer Johhny Rabb. Rabb has published the book "The Official Freehand Technique", which covers the gravity roll technique. The term "gravity roll" or "gravity blast," while common and accepted usage, is less correct than "freehand roll" or "fulcrum roll" in that the technique does not rely on gravity and can be played sideways, inverted, or in a zero gravity environment. A combination of the gravity blast and the bomb blast (i.e. both the kick and the snare is playing 16th notes in unison) is called a gravity bomb.