Mine is a bashed Sr. from plans purpose built for piggyback glider launching. One half of standard dihedral, Barn Door flaps and ailerons, conventional landing gear, totally modified tail surfaces with the addition of tail brace wires, bomb bay door, and many beef up mods. It weighs about 10 lbs and with flaps and ailerons can land much the same slow speed of a stock lightweight Kadet. Power is an OS 1.08, covering is Super Coverite with Randolph dope. Plane is about 14 years old and has been flown a bunch.