From PyroGuide

A Maltese Wheel also known as a Irdieden is an ground firework or a set piece comprised of intricate geared wheels and shapes covered with lances and Gerbs. They not only spin, but can also have spokes that move back and forth while spinning. They display three dimensional movements of wheels, diamonds and other shapes within the wheel that seem to move independently of each other. They are rarely seen outside of Maltese feasts or festas.

References

http://www.maltafireworks.com/video/video.html Malta fireworks
http://www.florianalocalcouncil.com/fireworks/main.html Malta festival of ground fireworks
http://www.malta.fireworks.usclargo.com/photo4.html About Malta
http://www.acepyro.com/irdieden/index2.html Acepyro

Pictures

http://www1.freewebs.com/vivatalgilju/groundfireworksfest07.htm#111714384 Lady of the lilies
http://www.slide.com/r/BLPzaZrr3T8b1JbeIj11eSyHvZ937DvT?previous_view=TICKER&previous_action=TICKER_ITEM_CLICK&ciid=72057594209622059 Malta Ground Fireworks Festival 2007 - 1