Lab Series stones are made of pure aluminium oxide for adjusting PFM alloy without any hassle of carbon contamination while Hardies smoothen away fine scratches and assure fast polishing of the metal surface, Use for chairside adjustments of nickel-chrome or chrome-cobalt prostheses and for polishing adjusted surfaces. Lab Series White stones for adjusting, Hardie points for polishing, Handpiece kit Available in a plastic kit, Use NP Alloy Adjustment kit for,  :,  non-precious alloys