Material: Soapstone is made of natural stone, and the penholder is made of high-quality aluminum, and has a long service life Product dimensions: The round soapstone refill is 1/4"x1/4"x5"(L*W*H), and the flat refill is 0.19"×0.5"x5"(L*W*H) Application: Suitable for marking steel, iron and aluminum, making clear marks for welding and metal manufacturing Design: The round bracket is shaped like a pen, which is easy to hold, carry and store. The flat soapstone bracket can be easily moved and filled just by pushing the thumb slider Package: You will receive 1 round bracket, 1 square bracket, 5 round refills and 5 square refills Soapstone is made of natural stone, and the penholder is made of high-quality aluminum, and has a long service life.Suitable for marking steel, iron and aluminum, making clear marks for welding and metal manufacturing.