ChargerLAB Power-Z KM003C Portable USB-C Fast Charging Tester PD3.1 QC5.0 Digital Voltmeter & Ammeter Power Bank Tester

The most capable analysis device for usb-c and thunderbolt at anywhere near this pricepoint, bit of an indulgence for myself but certainly if you are in the business of diagnosing usb/thunderbolt cabling issues you should have one

Absolutely fantastic bit of kit - for 30 days. I'm developing a 100W USB-C PD charger system and this made for really useful quick-glance check that things were as expected. It was working beautifully for almost exactly 30 days and then died one day outside of the Amazon returns window. Typical! I'll be buying another because when it works, it's great. Hopefully I was just unlucky with this first one.

This is a nifty little device that allows you to see the voltage, charging and (what I cared about the most) specs of Thunderbolt cables. There are tons of cables out there that claim to be Thunderbolt but they’re not. With this device you can check every cable. The only caveat: it’s very difficult to use and the online manual seems like it’s written by electrical engineers rather than by someone who understands what the average user wants to do and how to do it. So be prepared for some digging.

Bit of a niche product and a little expensive, but very useful if you have a pile of random USB-C cables and need to find their current, voltage and speed capabilities. Also good for interrogating USB-C PD chargers. Whilst I appreciate the compact size, it would be good if they made a slightly larger version with a bigger screen.