What is a jubilee clip?

[007 <jmel@netcom.com>]

Hi everyone:

Got a chance to go to the Brit Car Swap Meet in Dixon.  Got a few parts - 
B head, ZS carb, gasket set, & an old Haynes manual.

Reading thru the Haynes manual, I found a reference to a jubilee clip.  
Haynes sez that if you don't have a piston ring compressor, why then a 
jubilee clip is the next best thing.  So maybe our Brit friends from the 
other side of puddle can enlighten us poor colonials - What is a jubilee 
clip ?????

Thanks,

Jim Mellander