The problem: my Pioneer plasma TV has only 3 HDMI inputs. But I have 4 devices plus occasionally my phone (a Nokia, which also has a HDMI output). The solution: this little device. Blu Ray Player from Philips and a VHS-DVD combination unit of LG now hang together on this unit. Switching is automatic, ie I press the Philips, then naturally his picture appears. I start the LG, so his image is displayed even when the Philips still running. Conclusion: I now have a TV with 5 fully functional HDMI inputs. Oh, electricity is not needed externally. The device takes the power of the HDMI inputs. Could not be better. I have this good result is not expected - not for the money! Strong buy recommendation.