Blackmagic Quad SDI to HDMI 4K 2 - CONVMBSQUH4K2 - Mini Converter
Blackmagic Design HDMI to SDI 4K Mini Converter w/ Pelican 1060 Micro Case | eBay
Mini Converters – Models | Blackmagic Design
Atomos Connect Convert 4K | HDMI to SDI with Scale/Overlay (ATOMCCVHS2)
AJA Dante AV 12G-SDI/HDMI 4K Transmitter
Amazon.com: 4K HDMI to SDI Converter, Support 4Kx2K/60Hz HDMI 2.0 Input and 3G-SDI/HD-SDI Output, One HDMI in Two SDI Out, Auto Format Detection & Audio Embedder : Electronics