Review on 🔩 Bastex Countersink Carpentry Woodworking Adjustable: Streamline Precision and Craftsmanship by Keith Gonzales

These are special drills that are intended to make work easier. You can make the same hole with 3 different standard drill bits and all 3 should do this at the same time. It's not working. In particular, the countersink diameter is too small for larger bits and the taper of the bit itself is insufficient. The smallest three bits might work well, but there are other sets that work really well with smaller holes. I wouldn't recommend that, just use the 3 standard bits.