Hello, I would like to purchase this product, but I see that this is not designed 100% for metric system, so not a perfect fit for my 6mm and 8mm bits, but for 1/4" and and 5/16" size. Can I use it with my 6mm and 8mm router bits without problem or do I have to purchase a 6mm / 8mm router chucks separately? If so, can I use Makita ones or do you sell these items separately?