What age do you introduce the e-collar?

[Annette47]

About a year or so ago, I added an e-collar to my "bag of tricks" for obedience training my male (competition level, not just around the house obedience) and found it very helpful. I'd like to eventually be able to do the same with the pup, but didn't know what was a good age to start the collar conditioning (Mulder was 9 at the time, so obviously old enough!). I do train with people who have extensive experience using an e-collar in this venue, but they have different breeds, so I didn't know if what they do is necessarily appropriate for labs and certainly don't want to do any harm by introducing it too young or at too early a stage of training.

Thanks! By the way, I'm in no hurry about it, but am trying to plan for the future.