Length of nunchaku

Hello, as a professional martial arts instructor, I also found this problem when I selected the stick, most of the stick I use is not smooth, many movements are difficult to do, first of all, for the stick on the market for sporting goods now there is no standard ratio as a basis, coupled with the mass production, there is no professional nunchaku instructor as a technical guide to the production, so the nunchaku on the market is very confusing and the ratio is very serious. The length of your chain is very long, the standard length of the stick is 28 to 30, and the length of the chain is usually about 18, if you want to buy it, it is more formal on the Internet, but it is better to have someone who knows the stick to help you choose the right kind for you. I hope my answer can help you, thank you