Mounting Hole, The Opening Flange

member, is generally "parallel imports", which cause difficulties to the loading. Often due to individual small parts shortages, causing the whole assembly of parts scrapped;

Look protective layer for ease of storage, to prevent parts bump, before parts factory has a protective layer. Such as bushings, size bearings, pistons, valves, etc. are generally protected with paraffin, so that its surface is damaged, these important parts, the surface of the absence of the protective layer, mostly for "parallel imports";