Design for anti-corrosion: TEFLON coating on the surface, resistant to acid and alkali. Heating evenly and quickly: Utilize the anti-oxidant graphite block, which makes heating and energy transfer faster and uniforms the temperature between holes. Safety measures: adopt a novel method for insulating air ducts, maintain a very low temperature, and safeguard the operator. - Anti-corrosion design: TEFLON coating on the surface, acid/alkali proof. - Heating uniform and fast: Adopt graphite block (antioxidant), heating faster and energy transfer faster, temperature between holes more uniform. - Safety protection: adopt unique air duct insulation tech, keep the temperature ultralow, protect operator