you may want to call sportdog,give them the serial number and see if the owner registered it for warranty.
if the owner did register it,sportdog can call the owner for you and let them know you have it.
the folks at sportdog are great people,I bought a new four hundred model from just before pheasant opener here several years back,the batteries were bad out of the box.
I called them and they contacted the seller letting me know that I could trade it in for another one,problem was it had bad batteries as well.
evidently they had sat on the shelf at our local farm store for too long.
another call in to sportdog,I was a bit upset as my friends from Wis. were only going to be here for another two days and I was without a collar for my GSP.
they overnighted a new pro sport 800 !! that unit was almost two hundred more than the one I had bought and had twice the range.
I got a phone call from them asking if I had received it yet and they apologized for the trouble of the first two.
great folks that stepped up to take care of an issue that I feel was not their fault.
I blame the farm store for not checking dates and rotating stock like they should have.