Life expectancy of 580exII

I'm buying a couple of used 580exII flashes and was wondering what the average life expectancy is on one of these units. Is there and estimated number of cycles it can take?

Thanks

I don't think Canon has any spec for life expectancy. The 580EX II is a professional model that is used by wedding photographers and such. They do sometimes fail under heavy use, but so does every other piece of electronics. The 580EX holds up better under heavy use than most other flashes. They are far more likely to fail because they are dropped.

I know Syl Arena said that he got every different kind of rechargeable battery he could get his hands on and counted how many full power flashes he could get with a 580EX. After more than 25,000 full power flashes, one of his 580EXs failed. Note that in normal usage, most flashes are not full power.

So yes, if you use one enough it will fail. Flash tube will burn out or some other part will fail, but it does not happen very often. Most failures are because they are dropped.