Merge 2 HDMI channels into a single SBS HDMI channel (i.e. for dual play on 3D TV)
There seems to be an alternative for a very similar device for 58 euro:
Seach in aliexpress for :
1080P HDMI 2x1 Multi-viewer HDMI Switcher 2 in 1 out Seamless Multiviewer Switch Dual Display for Multi Media Devices With PIP
(sorry my new account does not allow me to add internet links)
You may want to add some HDMI audio extractors for each input HDMI channel to make sure that each viewer gets the original sound.