Non-Transitive Set of Four Dice

Non-transitive dice really work. I didn't try betting a friend, but I saw that 6/2 beats 5, on average, 2 times of 3, beats 4/0 5 times out of 9, and beats 3 1 time out of 3. 5 beats 3 50% of the time. At mathsgear.co.uk (I hope I remember that site correctly) they sell color-coded dice, but these work too.

These dice are cool. The numbering is easy enough to determine the trumping order without any calculations which is an important quality for dice like these.