Review on Adjustable Tapered Countersink - FTG USA by Colin Watkins

Half of these work well, the other half are completely crooked and unbalanced. Therefore, when you turn on the drill, the bits have a tremendous punch. This means that the drill bit does not rotate exactly over the center, but rather the drill rotates a wobbly circle around the center. If I didn't know to look for it before drilling, it would either break immediately or damage the part, or injure me from a recoil on the part.