This shell is designed to fit a Proto 2000 GP20 frame (must remove weights). The shell is also designed to accept Canon radiator fans http://shop.cannonandco.net/product.sc?productId=74&categoryId=12 1702 The shell includes holes for grab-irons and handrail stanchions such as those made by Smokey Valley. This is a new product that is still being tested and optimized; if you buy this, I always welcome feedback if you think of ways to improve the model.