Dwyer 160F-36 Straight Stainless Steel Pitot Tube 36 Inches Long is made out of tough and durable stainless steel and is etched with insertion depth graduations and a flow alignment indicator in order to help keep the pitot tube parallel with the air flow. The Dwyer 160F-36 has a straight design so it is easy to insert into ducts through grills and pressure taps.