Amazon.com: Optimal Shop 4X1 HDMI Multi-viewer HDMI Quad Screen Real Time Multiviewer with HDMI Seamless Switcher Function Full 1080P and 3D : Electronics
Ultra HD 4K Multi-Viewer 2x1 HDMI Seamless Video Switch(UHD-201MV)
HDMI Multiviewer Quad Screen with real time viewing and seamless switching