(#C4) Ecklund Flexible Thermocouples are specially designed for conducting heat penetration tests. Flexible thermocouples are Type-T and feature a 4" (102 mm) long insulated (24-gauge) wire thermocouple attached to a typical thermocouple body (the same body as a Needle Thermocouple). A flexible thermocouple installs into a Thermocouple Receptacle. When purchased, a flexible thermocouple comes with a Thermocouple Gasket installed.