That channel contains videos that the friend of a College student who was a victim of Slenderman uploaded.
There are 61 Videos, I believe, all together are around 1 Hour if im not mistaken, they are not that long each.
If you're the type of person into Suspense and Horror, then you should definitely check tha Channel. If you're the scary type (like me), then don't watch it by yourself in a dark room with no one around. I managed to watch SOME,because my house is a bit noisy during day, buy it still had those jump and eye covering moments.