The Flare Nut Sockets are ideal for use in narrow or confined spaces, such as working with wired temperature sensors, thermal switches, and Other Components. Work on ABS tube, master cylinder, coolant, and diesel injection sensors. This 12030 flare nut socket tool kit includes 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, and 19mm, covering a wide range of flare nut sizes. Use with 3/8" drive tools like standard ratchets, extensions, torque wrenches & breaker bars.