Advanced Materials & Tribology supplies Linear Motion Bush Case Unit. Advanced Materials & Tribology offers a wide range of Oil-less self-lubricated Bearings and Plates, Self Lubricating Bushes and Pump Bearings. Advanced Materials & Tribology is an ISO accredited company. The Linear Motion Bush Case Unit is a case unit with the standard linear bush installed in a small and light aluminium case. The Case Unit can be installed simply by bolting to a table.