DEXRON is the trade name for a group of technical specifications of automatic transmission fluid (ATF) created by General Motors (GM). The name is a registered trademark of GM, which licenses the name and specifications to companies which manufacture the fluid and sell it under their own brand names. Not all Dexron fluids are licensed for reselling under another brand name. All licensed Dexron fluids must have a license number that begins with the letters B through J. If no license number or "Dexron Approved" logo is found on the container, the fluid may not be GM approved and the fluid cannot be guaranteed to meet GM specifications. GM, like many automobile manufacturers, uses transmissions sourced from other suppliers or transmission manufacturers around the world; these transmissions are not manufactured by GM. Many of these automatic transmissions use unique fluids that might not be shown on this page.