Dayan+MF8 4x4x4
From Speedsolving.com Wiki
Dayan collaborated with MF8, another Chinese company, to produce a 4x4x4 Cube. It was considered one of the best 4x4's, and Feliks Zemdegs used it to break the average world record at WC 2011. However, without modding, the edges can often pop out if you try to corner cut too much.
