Morning Alan yes outputting from the HDMI port on the ST16 directly into the glasses, they work really well ensuring I can see the bird and screen, I have tried connecting others pilots devices via the USB C but to date have not mangled to connect anything other than my ST16, suits me fine.
The perfect complement to your DJI™ drone, Moverio BT-300 Drone FPV Edition smart glasses redefine First-person View (FPV), with a transparent display that makes it easy to view your drone’s video feed and key flight statistics, while keeping the aircraft in sight. This innovative display...
Been waiting for the HDMI "display only" style (BT35E) for some time, but actually waiting for the HDMI interface unit to be offered separately to simply add to my BT300 glasses... same glasses.
They also offer several optional upper clip on shades to block light above the glasses if not wearing a baseball cap. Plus additional clip on shades, I personally like the mirrored blue tint... a middle ground between the OEM dark & light tints.