High quality bits at an affordable price! I did many comparisons before purchasing this spoiler and was skeptical based on the old adage you get what you pay for. Fortunately, that saying doesn't apply to this purchase. The overall design of the bit is solid and precisely made. I noticed a stone less than 0.5mm at the bottom of the drill but was able to fix it with a diamond file. I am very happy with my purchase and expect it to last a long time. I'm using this with a Bosch 2.3HP MR32 router on a homemade router sled to align tiles/cookies. I've attached a picture of him shown next to a 1" spoiler board bat with a 1/4" shaft.