They also now supply an HDMI switcher, and inexpensive HDMI cables.
The HM-31 is their first such product, with three HDMI inputs and one HDMI output. The unit is HDMI 1.3 compliant.
It is powered by a 5 volt DC wall-wart which is included, and also has a remote control.
There are some switchers out there that are only operable with a remote control, and have no button on the front to select the input, but the HM-31 does have that button. This is a convenience thing, as the remote control is small and easily misplaced, so it is nice to be able to change the input without having to hunt down that remote.
When you plug the HM-31 in, it is always powered on. There is no on/off switch. Each input has its own blue LED indicator to let you know which input has been selected. The power indicator is a red LED. The input selection button is on the right.
The rear panel has the 5 volt input jack, an RS-232 jack, IR jack, then the HDMI output jack followed by the three HDMI input jacks.
Like many of you, I was surprised to find that I actually needed an HDMI switcher. I thought four HDMI inputs on my video processor would be enough. Well, it was, for awhile. Then I added a media server, and suddenly, I needed a fifth input. So, I wired the HM-31 such that the media server and satellite box go to two of the HDMI inputs, and the output goes to the fourth HDMI input on the video processor. Yes, it means switching two things to select the server or satellite vs. one of the other components, but so what?
Anyway, it worked perfectly, and now I don't have to manually unplug one component and plug another in its place in order to be able to watch any of five digital video sources.
If you thought four HDMI jacks for all your stuff would be plenty, think again. For sources 5 through 7, you will need a switcher. The Oppo Digital HM-31 fits the bill and is up to date with all HDMI specifications. For 99 bucks, it is something you may find you can't do without. (Also check out the inexpensive, i.e., $10, HDMI cables that you can order along with the switcher.)