Bördelverschlüsse, assembled with Septen. Septum butyl/PTFE (Polytetrafluoroethylene) Grey temperature-resistant from – 40 & deg C to 120 & deg C Splattering complete with PTFE coating thickness: 3.0 mm Pharma’s Septen Special Shape That Only The Contact Area of the probe with ptfe coating. On top of the glass has the elastic butyl or silicone and is very good sealing. Temperature resistance see above thickness: 3.0 mm.