This is a 1/144 scale Type-M Caquot observation balloon, as used by most combatants in World War I. There is a drainage slot on the bottom fin (since it's hollow, to keep the cost down), as well as a mounting guide-hole with reinforcement. (The mounting hole is conical, so you can drill it out to the size you need. Frequently it works well without modification.) The basket and ropes attach a three mounting holes on each side with slight built-in tension to keep them in place. The basket and ropes can be removed for storage.