（1）. SD6G bulldozer is designed on the basis of CAT’s D6D, and the main component of undercarriage is interchangeable with D6D’s, which is similar with D6D. We have accumulated twenty years’ experiences for manufacturing SD6D, so the SD6G’s undercarriage s reliable. The control valve for implement system is imported from PIRKER, which manufacture valve for CAT, so the implement hydraulic also enjoys a high quality.