Video Quad | Channel Video Multiplexer - 4x1 Hdmi Vga Quad Multi-viewer Function - Aliexpress
HDMI Quad Screen Multiviewer with seamless switching PIP/POP Scaler and Graphic Insert overlay Feature TCP/IP and WebGUI Control
A-Neuvideo 2x1 HDMI Multi-Viewer with PIP ANI-PIP-LITE B&H Photo
Amazon.com: 4K HDMI Multi Viewer Switch 4x1, Quad Seamless HDMI Switcher, 4 in 1 Out with Loop Split Screen, 5 Display Modes with IR Remote for Security Camera, Gaming : Electronics