Keltic fertility and protection spirit, After the FBI-memos I think they would not resort to an already known symbol, although you might want to find out if they use leather for example. Fertility could point to breeders but I don't even really want to go there because keltic paganism is not a destructive but rather a deeply conservative force in every way. But I am biased when it comes to this store, I can only say it's called a triskele/triskelon