This lens is made of acrylic and won't fade and yellow under sunlight in normal use.  The lens should last the lifetime of the bike.

This lens may break if the bike is laid down on it's side and the bike's weight presses against the turn signal.

Fortunately in many cases, the turn signal housing is fine and just the lens will need replacing.  This lens can be purchased and shipped separately for just this case.  AsianCycle is happy to help you reduce your costs by NOT requiring you to buy more than you need.  We can do this because we manufacture and distribute the parts directly from our own facilities in Asia.