You might notice that the case is a little larger in diameter, but is shorter in length than some of the other turbines. It is similar in size to the AMT Pegasus, wider but shorter case, and this turbine has an excellent reputation for offering great thrust while putting little strain on the components. It is operating at lower speeds, temps, etc. The Wren XL appears to be designed to operate with the same theory, great output while almost loafing along, all the while being very dependable. It seems there is plenty of foom to grow.