Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Work great!

As described, delivered on time. No complaints. Will purchase from this retailer again. These cole jaws work great. The only negative is the set up time every time you want to switch jaws. If you can afford it buy a seperate chuck just for these jaws. Mine came with grey rubber bumpers and they seem to work fine although I would hesitate to turn the speed up too high.Update: I agree with others; the grey bumper split when tightened. The optional bumpers are the cure.