The mf8 Son-Mum Cube is a 3x3 mixup cube designed by Mike Ambrust and produced by mf8. It features an outer 3x3 with a smaller 3x3 located on each center. As with most mixup style cubes, it is possible to scramble the inner 3x3 along with the outer 3x3 at certain irregular points, which allows the puzzle to be scrambled in some unconventional ways. It features both the Mike Ambrust and official mf8 logo.
Not completely satisfied with this product? We accept returns within 4 weeks (28 days) past the delivery date, for either store credit, or a full refund to the payment method — the choice is yours.
Our Promise to You
All of our products are guaranteed to be free of defects, or we will replace and reship at no cost to you. Please contact us within 4 weeks (28 days) past the delivery date to report any issues with items you have purchased.
Please note that some new cubes when being used for the first few times may experience what is termed a "pop". This is when one or more parts of a puzzle pop out without any damage actually being done to any of the pieces. This also occurs from time to time during normal usage. Pops are typically not considered a defect if the parts which come off can be reassembled by hand.
The corners on 2x2 puzzles should not be twisted as doing so may snap the piece. Damage caused by corner twisting is not considered to be a defect.
Fast & Free Shipping Available!
- Free standard U.S. shipping (includes Hawaii, Alaska, and AFO/APO) (2-5 business days) is offered for orders with a subtotal of $55.00+. Free expedited shipping (1-3 business days) is offered at $85.00+.
- All orders are shipped from our New York warehouse.
- Orders are shipped the same business day they are placed, or the next business day. The cutoff for same day shipping is 3PM EST.
- There is no processing/handling surcharge — all our shipping rates are at rock-bottom.
- We ship to all countries not sanctioned by the U.S. government.
- We advise that you look into your country's customs laws before ordering.
When I first got the cube it was so tight I could barely turn it. After loosening it, it turned out to be a great cube. I love the ingenuity of the puzzle
I have never solved a puzzle like this before but I am always up for something new. What a great challenge and a wonderful piece for the collection.
I got the stickerless version of this for my bday, and it is awesome. It is very challenging, but satisfying to solve. It is rather stiff, but that is unavoidable with a puzzle as complex as it is. Also, it rarely pops if you are careful, but when it does, it is pretty hard to get back together. The stickerless color scheme is great, but it is definitely not a speed cubing puzzle.