I've listed out all of the parts that I need to build an RG100ES from scratch, but there is one component I'm not sure of. I believe it's a thermistor, but no values are labeled next to it. Can someone provide some insight?

(Looks like a squiggly line with a circle around it)(All the way on the right to the left of the two diodes in the center)

http://el34world.com/charts/Schematics/files/randall/Randall%20RG100.PNG

Please help! Thanks!