1.longer life: more 20hours on tombstone 2.better used with CNC machine 3.support online order by Escrow 4.factory price vacuum brazed diamond point tools bits for caving tombstone,stone marble granite letters and relief Product specification:C1----C20 shank: 4mm, 6mm, 8mm, 10mm, 12mmCed:3mm,4mm,6mm,8mm,10mm,12mmCel:7mm,9mm,12mm,20mm,30mm,40mmAngle:20,60,90,120Ovl: 40mm,45mm,50mm,60mm,70mm,90mm, ...