The holder for the fiberglass work like a mechanical pencil, and by turning the end of the pencil the user can extend or reduce the exposed fiberglass insert. A new fiberglass refill insert may be inserted into the pencil when needed.

The fiberglass insert is designed for removal of investment from castings and the removal of oxides or other discolorizations from cast or machined metal.

The user should use this instrument in front of a vacuum and wear both protective glasses and breathing masks to eliminate either breathing or absorbing the airborne fiberglass particles.

The holder for the brass pencil works like a mechanical pencil, and by turning the end of the pencil the user can extend or reduce the exposed brass insert. A new brass refill insert may be inserted into the pencil when needed by turning as well.

The brass insert is used to remove debris and clean burs and other cutting instruments. The brass is soft and may leave a small brass residue.

The user should use this instrument in front of a vacuum and wear both protective glasses and breathing masks to eliminate either breathing or absorbing the airborne brass particles.