I am not into light aircraft. But if you look carefully you'll see it is G-OLFY iso G-OFLY.
G-OFLY is Cessna 210 Mode-S code 402277.
This aircraft send along Mode-S code 406A6F and should be new G-OLFY Breezer B600.
Was at Rotterdam approach as G-..FY and flight started in Bredstedt Germany that's where they assemble the Breezer B600.