Features and Benefits:Permanent magnet sticks to any ferrous metal surface;Keeps small metal parts and tools from getting lost.;Sticks to any ferrous metal surface;Rubber coating prevents scratches.;Even works sideways or upside down;Sizes (diameter): 4" and 5-1/2";Permanent magnet sticks to any ferrous metal surface. Keeps small metal parts and tools from getting lost. Sticks to any ferrous metal surface. Rubber coating prevents scratches. Even works sideways or upside down. Sizes (diameter): 4" and 5-1/2"