Baguenaudier (pronounced [baɡnodje]; French for "time-waster"), also known as the Chinese rings, Cardan's suspension, Cardano's rings, Devil's needle or five pillars puzzle, is a disentanglement puzzle featuring a loop which must be disentangled from a sequence of rings on interlinked pillars. The loop can be either string or a rigid structure. Variations of this include the Devil's staircase, Devil's Halo and the impossible staircase. Another similar puzzle is the Giant's causeway which uses a separate pillar with an embedded ring.