The eponymous Predator elements have developed over time. The principle behind the project, however, involves attaching rubber strips to the forefoot that Adidas says increases the speed of the ball. The initial focus in Predator commercials was on shooting strength, but this gradually move more to the effect on ball spin and precision. The first Predators were also available without Predator elements under a different name. While the Predators were made of black kangaroo-leather with white stripes and red elements, the equivalent boots without Predator technology were black with white stripes and blue accents. The Precision equivalent, however, was black and white only, while the Supernova (Predator Mania without the Predator elements) was black with either silver or gold heel caps and stripes. David Beckham wore these boots for most of his career, as did Zinedine Zidane.