This thing is a glider that can be launched using a rubber-band.
I print these out of PLA. You will need a descent set up as the rear wing is only 2 layers thick! when removing this from a print bed I recommend grabbing the nose of the plane and lifting it straight up off the bed slowly. Try to orient the plane on the bed so the first layer in the wing prints from right to left, this will help when the wing is bent into place. My Prusa prints solid layers at 45 degrees using the X and Y axis together so this means the plane is 45 degrees on the bed.
Finishing and preparing to fly the Glider model
Glue the rubber band launching hook in the pocket below the nose of the plane using CA glue.
Apply a small amount of glue to the pockets between the wings and the fuselage. I use a wooden toothpick to make sure the glue gets down into the pockets. Then use a medium sized binder clip to hold the wings tight to the fuselage while the glue dries.
The 12 degree angle in the main wing is a self leveling feature that will ensure the glider flies straight. Using a substantial rubber-band attached to a stick or dowel draw the plane back holding the rudder and release it to send it flying! A small amount of up and down elevator can be bent into the plastic to adjust flight behavior.