CS4015 with the balanced size, can be used for fire necklace / keychain fire starter kit, and worked with large ferro rod. Even gloves on.
# 5*90-degree ridge.
# Real test- After 12,000 strikes no blunt at all.
# Material: Zirconia Ceramic ( Second to diamond ).
# Weight / Size : 6g / 40*15*2mm.
# Hole size: 4mm ( Can through normal paracord ).