These are a must have for CBR's (along with the openers). They are heavy duty quality and worth the investment to keep your jewelry in good condition. I even was able to fix three CBR's that i beat the crap out of long ago and far away by using taped pliers (kids, do not use ordinary pliers at home) which now are good as new. I live the grooves in all the right places to seat the rings and beads while working with them. Yay!