This is a daylight kit for a Yours C28 Serena. It's no longer needed due to a specification change. It was used for about six months and functioned normally until removal. https://yoursshop.jp/smartphone/detail.html?id=000000002606&srsltid=AfmBOoqsDW5qqccjoCMefWULfQq5XxdgtUOreqJLYU-vEP-L5cKf6LO5 Installing this improves daytime visibility, thus enhancing safety. I think it's a desirable feature for C28 Serena owners. The instruction manual has been discarded, but it's easier to understand by watching YouTube videos than reading the manual, so I think you won't have any problems by referring to them. The double-sided tape used to attach the main unit is not included, but please obtain it from a 100-yen shop or similar. Since it doesn't require modification of the original wiring, it's easy to install and remove. Also, it can be turned on and off with the main unit switch. I think it can still be used, so thank you.