This is Quinsequential Gamma (3 cm) the third version of the Quinsequential design. Quinsequential Alpha required 9 separate moves before the first piece came free. Quinsequential Beta improved that to 11 moves, and now Quinsequential Gamma is ready for public viewing with a respectable 13 moves for first removal.
As far as I know, this is a record for a 5x5x5 cube, so I am laying down the gauntlet!
I have given the design a nickname of 'The Switch Cube' - you'll understand why when you've solved it!
Available in four sizes to suit all budgets.