It's a neat little hammer and punch kit. You can keep the brass head and steel head in the hammer for a bit more power, or remove them both and use the plastic head only for delicate tasks. For lite use, such as driving pins, this kit is perfect. The punch fits inside the hollow handle. Think: "lite use" with this kit. Alloy of copper and zinc. Commonly contains lead. May include iron, manganese, aluminum, silicon, or other elements.

I used this specific kit to build my newest AR-15. The roll pin punches have a small nipple/notches that assist in keeping the punch square on the roll pin itself, preventing it from slipping off and damaging your firearm. This is a very nice feature that came in very handy when tapping in the roll pins. Alloy of copper, usually with tin, but sometimes other elements, including manganese, phosphorus, silicon, and aluminum. Better conductor of heat and electricity than many steels. Corrosion resistant. Brittle, hard, resists fatigue. Usually a slightly higher melting point than brass. Bronze sculpture, bells and cymbals, mirrors and reflectors, ship fittings, submerged parts, springs, electrical connectors.