Here's An Easy Way To Drill Your Pearls - This Nickle Finsihed Brass Tool Holds Your Pearls Securely As You Drill. Textured Locknuts Give A Secure Hold. Works With 13 Sizes Of Bead (0 - 10mm).* Textured Locknut Provide A Secure Hold * Works With 13 Sizes- From 0-10mm * Professional Quality