15A long spring 16 cm long
             
                15A30A high valve
             
                15A30A high baffle
             
                15A30A70A low valve
             
                Indium tin alloy wire
             
                Mountain-shaped tungsten wire usage demonstration
             
                Ordinary aluminum strip
             
                Nickel-chromium wire
             
                Aluminum wire
             
                Lace aluminum piece 20x4x0.2
             
                High-purity aluminum sheet 22x11x0.2
             
                High purity indium wire