[Number of substances type]: 15 [Formula]: outdoors diameter of substances (addendum circle) = (number of teeth +2) * modulus [Gear model ]: 1. 1007A 2. 1008kxb 3. 1008X 4. 1008H 5. 1008A 6. 1009A 7. 1010A 8. 1012A 9. 1014A 10. 1016A 11. 1018A 12. 1018D 13. 1018F 14. Worm 6*6mm 15. Worm 6*10 Package Include: Gear set x 1