The ATH100K1R25 series thermistor consists of three  versions, ATH100K1R25,  ATH100K1R25T70 and  ATH100K1R25T70S. The ATH100K1R25 has bear leads  coated with copper, the ATH100K1R25T70S has the leads  covered by high temperature plastic tubing and sealed by  epoxy, while the ATH100K1R25T70 is the non-sealed  version.  The ATH100K1R25 is of a high stability and high precision  glass encapsulated thermistor. Comparing with conventional  epoxy encapsulated thermistors, ATH100K1R25 features  much wider temperature range, especially on the high end,  much better long term stability, smaller size, and shorter  response time. In addition, there are two insulation versions  available, one of which comes with leads covered by plastic  tubing, the ATH100K1R25T70, and the other one, the  ATH100K1R25T70S, is sealed between the head and the  tubing.