The 1/2" flush-cut router bit came today. I mic'ed it, and it is just a few thousandths shy of 12.7mm. I put my old 3/8" / 9.5mm bearing on it, with a spacer I made from a tiny washer, and did a test cut. Then I swapped the bearing for 10mm and did another. These Yonico bits are nice because they color-coordinate with DeWalt tools !