The new steel fully wrapped gear provides more safety and durability. Our electric tufting gun have nstalled internal over-voltage, over-current & short-circuit protection systems to avoid accidents during use. There is an adjustable speed knob at the bottom, you can easily adjust the frequency and speed you need. Adjustable range: 5-40 stitches/second. We have made improvements to the operation buttons, which are more convenient for you to use the tufting gun. All these will provide you a more perfect and comfortable experience. Cautions: After plugging in the power, do not press the black button before turning on the switch, otherwise it may be damaged. Since there is still current on the circuit board at this time, pressing the black pin button will damage the power capacitor on the circuit board. Make sure to turn on the power switch before pressing the black button. Never loosen or adjust the bolts underneath. This will cause the scissors to not work. When operating the tufting gun, keep it in the correct direction, the wrong direction will cause tufting failure. Always keep the tufting gun closed when threading. It is best to unplug the machine to avoid accidental startup. Be careful when adjusting the lint cutter. Incorrect adjustment of the machine will cause the scissors to not work. If the lint height is adjusted too high, the scissors will not work properly. Please follow the operating instruction to make appropriate adjustments. Notes: Please allow a slight error in size (manual measurement). There may be slight differences in colors due to different screens. Please keep away from children (pointed parts contained). Notes: Please allow a slight error in size (manual measurement). There may be slight differences in colors due to different screens. Please keep away from children (pointed parts contained).