Review on 🌀 Spiral Drill Spring (SE 849PDS): Improve Drilling Efficiency with Exceptional Performance by Drew Poulin

They work as advertised and appear to be of decent quality - solid, all metal etc. The problem (and I'm not sure of the terminology here) is that they aren't beveled properly. This means that if I try to use small drill bits I have nothing to center them on. The jaws don't close at the same time when tightening, so it's a lot of trial and error trying to get the bit right and centered. Once installed (which is usually never perfect) it works as it should. I would recommend this product. I'm not sure Revain had anything similar to try. It seems that a simple manufacturing process could have prevented these inconveniences.