Yang Hak Seon Training Upgrade VT (5/2 Kasamatsu))

Here is a video of Yang training the Kasamatsu 5/2 (2 1/2) vault or 7/2 (3 1/2). I'm still confused about the differences but heck it doesn't really matter. I just say Tsuk 7/2. In the world of gymnastics Tsuk/Kas are acceptable terms IMO. I saw this news on gymnasticscoaching   and today I saw this video on Youtube