PRECISE - The filament tip makes precision burns even on the finest threads and knots ONE - Tip heats up instantly with the push of a button! Can heat-up up to about 700 degrees F/371 degree C in a matter of 2-3 seconds High Quality - The burning thread pen is made of tungsten wire material with fast heat conduction speed, with good performance and durability in life PROFESSIONAL FINISH - Burn excess string at the edge of the knot, creating a clean finish BATTERY OPERATED - The for zapper uses 1xAA (1.5V). Get multiple hours of use from this tool with just one battery