Cummins is a leading manufacturer of diesel and other engines used in heavy- and medium-duty commercial trucks, off-highway equipment, and locomotives, in addition to prime power and standby generators. The company also sells powertrain components, which include filtration products, transmissions, turbochargers, aftertreatment systems, and fuel systems. Sales are approximately 60% US and Canada and 40% rest of the world. Much of Cummins' foreign sales (China, India, and so forth) are through joint ventures. The company operates 650 distributors and over 19,000 dealer locations across 190 countries. Cummins' business model is unique as it competes with many of its heavy-duty truck manufacturer customers, which also make their own engines.