There are currently only five YouTube channels that have received this award two individual YouTubers: PewDiePie and MrBeast, as well as three corporations/brands: T-Series, Cocomelon, Like Nastya, Vlad and Niki, and SET India.
The Red Diamond Play Button is a special award by YouTube given to channels who reach 100,000,000 (100 million) subscribers. The Red Diamond Play Button in YouTube's promotional video.
