About Us CNB PARTS CO. , LTD , located in Xiamen , Fujian Province , China , the manufacturer of undercarriage parts for excavators and bulldozers , such as track roller ( bottom roller / lower roller ) , top roller ( carrier roller/ upper roller ) , wild assy ( front idler ) , sprocket & segment , and track chain ( track link assy ) for Komatsu , Caterpillar , Hitachi , Volvo , Kato , Daewoo , Hyundai , Samsung , Sumitomo , Kobelco etc.With about 18 years of the uninterrupted efforts and being absorbed in production , Our products , undercarriage parts , have been sold to about 21 countries from Southeast of Asia , Europe , Middle East and North of America and so on.Our external sales team can try all efforts to offer the best service and the top first-class products to our clients .