Ask the archer: Where is the shaft on the bow?

The first question, Xuan Kou should be slightly higher than 2 mm with reference to the arrow platform. If the arrow used is thicker than 5 mm and slightly higher than 4 mm, the second question, the arrow should be cut Xuan, and the right bow is slightly to the left. I adjusted the bow 100 times. It would be more convenient if you could tell me what bow it is. If you have any questions, please keep asking questions.