These are high environmental resistance Fibers. With the case and Fiber sheath made of PFA, the Fiber can be used with various types of chemical liquids. The Fiber core will not harden or break, even in environments where oil is present. These Fibers deliver stable detection since the sensing part is sealed with fluorine resin, which does not allow oil penetration. Additionally, the detection part features a convex design made of fluorine resin, achieving lower friction than glass.