TYPE 1 Window Wiper for Series NW50 Sight Glass [TY1WW/NW50]: The Type I window wiper features a direct, thru-the-glass mechanism that reliably wipes away residue on the inside surface of the lens. Depending on the size of the lens Type 1 Window Wipers are suitable for pressures up to 75PSI [5 Bar]. emperature ratings range from: 350°F [177°C] with a Silicon blade to 400°F [204°C] with PTFE blade. All interior wetted parts of the Type I wiper are constructed of stainless steel. CUSTOM WINDOW WIPER ARRANGEMENTS ARE AVAILABLE UPON REQUEST.