Review on 🐏 Big Horn 4 Inch Self Centering (Model 19138) by Brian Rogel

they do exactly what they should and are durable for use in a drill. The only thing you need to know is not to play with the socket head screw which is on the bottom. just leave it alone and use it as is. because if you fiddle with it, the tension of the spring will make it fly out of your hand and fall apart, which is not good. So the advice is to just take it out of the box and start using it.