The hockey puck puzzle is a mechanical puzzle sold at
http://look.net/hockeypuck/
and has a few web pages devoted to it:
http://web.usna.navy.mil/~wdj/mball/puck.htm
and
http://www.geocities.com/jaapsch/puzzles/puck.htm

Label the 24 pieces =1, -1, ..., +12, -12.
The rotation r sends
(1,-1,...,12,-12) to (12,-12,1,-1,...,11,-11).