The USBC-VAMETER is designed for USB-C Power Delivery Revision 3.0 (5-20 volts, up to 5 amps, 100 watts maximum). Most devices currently on the market use PD R3.0.
The USBC-VAMETER3 is designed for the latest USB-C Power Delivery Revision 3.1 Extended Power Range (EPR) (5-48 volts, up to 5 amps, 240 watts maximum). As of July 2022 there are not many EPR devices available yet, but a good example is the 16" Apple MacBook Pro with 140W charger.
If unfamiliar with Extended Power Range feel free to take a look at our blog post on this topic here: https://plugable.com/blogs/news/what-is-240w-usb-extended-power-range-epr