LONG-LASTING - Specially designed for use with all 1/16" arbor parts in 1/8" collet (e.g. pencil grinder or rotary tool) - Top quality magnetic mandrels are nickel plated with stainless-steel screws. Arbor : 1/16" (1.6mm) Dremel Code : Miscellaneous Shank Diameter : 1/8" (3.18mm) Shank Type : HP Tool : Rotary Tool Tool : MOTO-TOOL