This model motor measures 11 1/2 inch in diameter and only weighs 16 ounces when completed. This will give your model a better useful load better spent on battery weight. The cylinders are separate from the case so the diameter is somewhat adjustable from 11 1/4 to 11/3/4.This model is not intended for glow powered models due to the fuel proofing requirement. Please go to the free instructions located under the parkflyerplastics banner on the home page to view the instructions before purchasing this model. The construction takes some time to complete hence the good price for the kit. Note that the aluminum tubes are not included but are listed along with the paint and adhesive used.