In case other interested folks weren’t aware (as I wasn’t until last week), Chris Abell has now added a high G whistle to his offerings (so, that’s now, low to high: G, A, Bb, B, C, D, Eb, E, F, G).
He will be adding a low F to his catalog before too long.
Cool, the Abell Dog Whistle, gotta have one! 
Loren
That’s OK, I don’t have an obsession with sets of things…
Trisha
The Abell high F is, um, really high. I like it, but it’s, um, really, really high. I don’t think I want a high G (miracle of miracles).
Well, you need a dog, then you’ll want one. 
Loren
I’ve been dreading waiting to hear when he’d come out with a low f. What do I tell my wife??? I’ve already sold off my children to amass my current whistle collection. Well, I guess she has to go too. (Or else, she has to get a second job.)
Tony
Great! I’ve still got all mine
Trisha
Is THAT what I need to do? Cool! Anyone one in need of 10, slightly used, children? I’ll ask a reasonable price…