model:
Aperture 6 * 6 (center distance 10)
6 * 6 (center distance 15)
6 * 6 (center distance 20)
6 * 6 (center distance 25)
8*8(15/20/25/30)
10*10(15/20/25/30)
12*12(15/20/25/30)
14 * 14 (center distance 20 / 25 / 30 / 35)
15 * 15 (center distance 20 / 25 / 30 / 35)