OS Engine 21501030 Crankcase Max .12 .15 CV-R CVR Engine Block Case. This item is new. This is a genuine, factory-sealed replacement aluminum crankcase (engine block housing) for high-performance O.S. Max .12 CV-R and .15 CV-R nitro glow RC car/truck engines. Please see pictures and let me know if you have any questions. Thanks for looking!