Gravity Defyer are a shoes manufacturer that launched their shoes in 2008, featuring a spring component as part of the sole to improve shock absorption. They were initially known for their initial logo that had a design reminiscent of sperm. The company produces a wide range of performance footwear, everyday shoes, and dress shoes. https://thefootwears.com/the-ftc-complaint-against-the-gravity-defyer-footwear/