Monoprice HDMI Coupler (Female to Female) - Monoprice.com
Tripp Lite HDMI Compact Adapter Coupler HDMI FF HDMI coupler HDMI female to HDMI female black - Office Depot
Amazon.com: UGREEN HDMI Coupler 2 Pack, 4K@60Hz HDMI Female to Female Adapter HDMI 2.0 Extender for HDMI Cables 3D HDMI Connector Compatible with HDTV Roku TV Stick Chromecast Nintendo Switch Xbox PS5/4