... 's surface is treated by molybdenum and hard chrome plating,the second rings are usually treated ... / phosphating ,the oil rings are treated by hard chrome plating/ gas nitriding/phosphating.All kinds of merchandise ... , O309, L4088742+2.5+4FP-BE19OM602D25874,5,62.5+2+3FP-BE20OM615DB200D ,220D,Unimog8743+2+4FP ... 2+3.5FP-BE27OM603 D35A,OM601300SD 350GF Turbo894.62.5+2+3FP-BE28M104E28S280, SL280 S32089.961.5 ...