#305 Sharpening Stone for the Handpiece #305 Sharpening Stone for the Handpiece SS305 Mandrel Mounted Stone for the handpiece restores the cutting edge on dull instruments. Stones are made of white aluminum oxide. Where to Buy x Category Dealer PartnersSales RepresentativeStrategic MarketsSchools RepresentativeAccutron™ Equipment Sales Zip Code Find RepresentativeReset Select a category, input a zip code and click on Find Representative, or explore the complete list here.