Shox is technology developed by Nike and incorporated into several of their flagship athletic shoes. Shox are small hollow columns that make up the midsole of the shoe. They are mostly made of rubber. There are many different formations that Shox come in, but they usually come with four circular columns in a square formation for maximum cushioning. There can also be five or six Shox that vary in height, and triangular and rectangular Shox that provide better stability. Some shoes have midsoles made entirely of Shox, like the Nike Shox NZ and Nike Shox TL series.
The first shoes to use the Shox technology were introduced in late 2000, the Nike Shox R4 runner, the BB4 basketball shoe, and the XT4 cross-training shoe. Nike claims that Shox NZ Shoes not only absorb impact from heel strike while running; they also "spring back" and add more power to a runner's stride.