This is a fully functioning combination lock. No glue required. The combination is 2718(starting from the place closest to the shackle). To assemble, place wheels in the slots, put the shackle through the holes in the wheels, then snap the small cap into the back to keep the shackle from coming out when you unlock it. To tell which wheels go in which slots, the correct digit of the wheel is across from the small square on the wheel.