The Estes D12-0 engine is a booster stage engine designed for model rocket flight and has to be used with a standard engine. This engine is for flights in rockets weighing less than 14 ounces, including the engines. Each package includes 2 engines, 2 starters and 4 starter plugs.
2 - D12-0 Engines 2 - Starters 4 - Plugs
ENGINES FOR MODEL ROCKETS