Parker ball bearing rotary fittings are used to connext a fixed point to a rotating, swinging or moving part via hoses. These products are used to prevent torsion and small hose radius. The ball bearing rotary fittings are suitable for hydraulic oils and lubricants on minerl oil base as flow media. The construction of this service-proved product range is characterized by a compact, maintenance free construction. The ball bearing rotary fittings have a combined ball and plain bearing with constant lubrication, a low starting torque and wear-resistant annular piston sealings.