Each wing half has a 1/4" tab. Once the two halves are joined together with a 1/4" ply joiner (temporarily or permanently) they key into a 1/2" wide slot in a fuselage bulkhead, you can see all this in the images above but it's a different way to do things and I was initially confused until I got the kit (I'm at the same point in the build). Two conventional wing bolts at the trailing edge then hold the assembly together for flight. This isn't a 3D plane so this seems to be a perfectly reasonable and innovative wing attachment scheme.