Most motion applications are perfectly well-served by mechanical bearing guidance; but there are many cases where precision, angular repeatability, and geometric performance must be optimal or where submicron bearing rumble is problematic. An air bearing stage can help in these situations. An air-bearing stage is a rotary or linear positioner that floats on a cushion of air, using one of several preload mechanisms, nearly eliminating mechanical contact and thus wear, friction, and hysteresis effects. These are the most common indicators that an air bearing stage might be the right choice for your application (s. Fig. 1).