Hudson Bearings flange mounted four hole stainless steel ball transfer. Ball transfers solve a variety of material handling and motion control challenges, whether used in the traditional ball up position or as a caster in the ball down orientation. Ball transfers offer advantages to traditional casters, such as lower profiles and omnidirectional movement, often at a lower cost. Common applications: air cargo, shears, robotics, military logistics, store fixtures, die handling, laser and plasma cutters, glass and metal manufacturing, medical devices, caster substitution. Made of stainless steel housing material. Ball support cup is hardened and plated. Protective cover assures low torque and longevity. Units available in plated carbon steel to provide corrosion resistance. 1-1/2-inches main ball rotates on ninety 3/16-inches support ball.