The AIRMASTERS Air Knife has proven to be of high quality, high performance and one of the most quiet, designs. The AIRMASTERS Air Knife are made of aluminum and coated for long life. Stainless steel models are available for high temperature and corrosive applications. The AIRMASTERS Air knives comes complete with a stainless steel shim to set the air gap and are held together with stainless steel screws. They can also be coupled together using a coupling kit for longer spans.