The Siemens 192-633 Needle Probe with Calibration Cover Wrench is a precision temperature sensing and calibration tool used in HVAC control systems. The needle probe accurately measures air or fluid temperature, while the included wrench facilitates secure installation and proper calibration. Designed for use with thermostats, controllers, and building automation systems, it ensures r... https://www.partshnc.com/test-probe-wgauge-and-wrench