Configuration of turtledove under 20 meters slingshot

Excuse me, do you want to ask the question "what is the configuration of the turtledove under the slingshot 20 meters?" The shape of the turtledove 20 meters below the object is as follows:

1. Flat rubber band thickness: 0.6-0.8mm. ..

2. There is no slingshot model. 25 15, steel ball size 8, wings 1745 or more, 8 mm or more.

3. Head and neck: 2040, 6 mm is enough, and the back 1745 or more, 10 mm or more.