Flexible boot

A flexible boot having a bellows and mount portions on both axial ends of said bellows at which said boot is mounted on mechanical elements, said flexible boot comprising:

• an anti-degradation agent make-up element including at least one ring fitting in at least one valley of said bellows, said at least one ring being made of a rubber or rubbery material which contains an anti-degradation agent and which is capable of allowing said anti-degradation agent to precipitate on the surface thereof, the content of said anti-degradation agent in said anti-degradation agent make-up element being large enough to cause the precipitation of said anti-degradation agent on the surface of said material, said anti-degradation agent make-up element being fitted on at least a portion of the outer surface of said bellows so that said anti-degradation agent precipitated on the surface of the material of said anti-degradation agent make-up element is caused to progressively immigrate into the material of said bellow thereby making-up said anti-degradation agent in said bellows.