There is a alum tube wing joiner and some wing nuts that hold the wing in place ,it runs through a glass tube in the fuse .Not a bad set up by any means .My 120 OS pumped is a tad bit lighter than the 120 YS 2-3 oz I think I have not been able to get my engine dialed in quite the way I want it yet but it still hauls the plane around good .Vertical is not unlimited but a prop change will help that .Good luck :-) !!!!!!!!!!!