This Precision Extension Test instrument is a highly accurate milliohm meter. It can be used to test 3 wire extensions for hobby servos, etc.
Why get one? Most extensions and switches have crimped on terminal ends and often the quality is bad. A high resistance extension can lead to loss of control and expensive damage. This instrument will analyze and tell you the resistance of any extension you want to test. In addition, it will test on/off switch resistance of any switch using standard extension connectors.
Pays for itself the first time you find a bad extension and replace it before you have a crashed plane, heli, car or boat! For more information please see https://www.rcgroups.com/forums/showthread.php?4733219-SwitchIR-Project-%28Including-Video-on-its-use-It-will-be-commercially-available%29 and https://www.rcgroups.com/forums/showthread.php?3590441-Switch-IR-meter-revisited
Extension-Tester-Instructions-r1.0
Notes:
- Standard 9V battery not included
- Power Switch does not light.
- Wire colors are black, red, white, you can use the brown, red, orange extensions also
- QR code on front connects to the instruction manual
- Here is a table of wire resistances: Resistances of Ideal Extensions













Joshua Orchard (verified owner) –
Absolutely perfect tool for the shop. I’ve immediately come into my own for spring maintenance and including this tool in my workflow. I’ve been SO impressed with this tool that I made my own little review of it. Money well-spent on a tool that IMO is now a standard for any RC modeler.
https://youtu.be/9PrqRK9eZbc