Comparison/teardown/pictures between build quality of ruipro and FeizLink (another ~£50 optical contender)
https://www.avforums.com/threads/fibre-optic-hdmi-ruipro-vs-feizlink.2288083/page-2
https://www.avforums.com/threads/fibre-optic-hdmi-ruipro-vs-feizlink.2288083/page-2