The Happy Thruster is an addition to the Happy Seat - they were developed for use together. The Happy Thruster slides over the Happy Seat while deflated and stays in place while inflated. The purpose of the Happy Thruster is to turn your kayak into a spaceship. There is no other system that will give you more lift for huge air than the Happy Thruster! The benefit of this system is the ability to make quick adjustments to the amount of volume you add AND, it is a soft pillow in your spray skirt that protects your face and hands.