Rocket nosecone model, removable, hollow, internal ridge for mounting on tubular body. STL format, binary encoded. Profile is double parabolic with conical tip. That is to say, main profile is a parabolic curve continued seamlessly with a second parabolic curve identical to it but disposed symmetrically with respect to the perpendicular to the tangent to the point where the first curve ends. Main parabolic curve is capped with a cone tangent to it at the transition point.Used 123D Design app, free from Autodesk.