Fixing gun works on concrete, iron, aluminum... etc. And most common surfaces used in markets and common among most people and homes. IMPORTED FIRING NEEDLES: Imported firing needles (firing pins) DOUBLE SILENCING: Double silencing FIVE LEVEL ADJUSTMENT: Five-level adjustment NOT PICKING NAILS: Nails do not get stuck (or does not hold nails, meaning nails do not jam during use) 100% QUALITY GUARANTEE: 100% quality guarantee