Expertly constructed with large main contact ball seated on a quantity of small bearings in a hemispherical cup. Not just a single ring of balls. The main ball rotates freely and instantaneously in any direction. Extremely heavy loads can be moved in any direction with minimum effort. All units are fitted with a sealed washer and therefore self cleaning. Pre-lubricated - almost maintenance free. Some units provided with oiling points. Supplied in mild steel carbon units zinc plated or stainless steel throughout. Illustration right shows a wide variety of standard fixings available which enables them to fit to wood, metal, plastic, tube, slotted angle etc. To determine ball unit capacity the weight of article to be conveyed should be divided by 3, the answer gives the maximum load which any single ball unit may have to bear. Spacing pitch of units is obtained by dividing the narrowest dimension by 3.5 this ensures 3 units beneath the narrowest dimension at any one time. (Enquire for additional ranges.)