1. Material: High speed steel. 2. Application: mainly used to cutting Acrylic etc. 3. Exellent quality ... steel.double flutes spiral bits, more stable while cutting things.2.Model detail: CED-8mm, CEL-20mm, SHK-8mm, OVL-70mm3 ... , resonable price and considerable after-sale service. two flutes spiral bit for Acrylic( HSS milling cutter )