Ok, this weekend I made a Low G. I wanted something to get used to the piper’s grip, but the Low D seemed too much, so I made this shorter whistle.
I think the next one will be a Low C, mainly to feel the difference.
Well, thanks to this nice key, for the first time in my life I managed to “play” something on a low whistle 
I’m very, very happy!! It is not easy (for me at least), and I still can’t play at a decent speed, but anyway, I recorded a soundclip to let you hear the sound. Is not the best whistle I got, the sound is airy, requires a decent amount of breath, couldn’t hit the third octave, but I like it anyway because is my first Low G 
But it can be considered quite sweet and mellow, too 
Ok, here are a couple of pics with a High D and a Low D for size comparison:
And here is the soundclip. Yes, I know it sounds like being played by a whistle newbie, but I am actually a whistle newbie, so I think it’s OK 
SOUNDCLIP: Down By The Sally Gardens (well, kinda actually; shortened a bit)
And lastly, I appreciate if anybody can tell me the diameter of the soundholes of a Low C as I don’t own one for comparison