and Hard - The cutter head is made of Tungsten steel. This knife pen has much higher hardn than mon metal blade. It can engrave words on metal and glass. Durable - Advanced Tungsten blade is wear resistance and no rusting,lasts up to 7 times lonr than mon metal blades. Refillable Knife Refill - Replacing the blade is as simple as replacing frequently-used refill. We supply refills for good prices and convenient chasing. Like Writing - Using the craft utility knife feels more like writing than cutting. Portable push-type pen design is convenient to carry and store. Safer than normal craft knives. Ideal for Craft Works - Designed for thin sheet materials,such as washi tape,paper,freezer paper patterns,RC model vinyl,planner stiers,cards and so on..