I'm having some issues with right hand positioning and wondering if this gadget would help.
I quite often catch the side of the 2nd trill key with my right ring finger. I don't easily maintain the recommended position of the right hand roughly at right angle to the flute with nicely curved fingers. rather it seems that my fingers tend to be too straight and somewhat pointing diagonally away from me and I think my thumb is moving around causing the wrist to swivel towards me.
Well, that's probably mud clear! But any thoughts on the Thumbport?

Several of my pupils use it, and all have found it helpful. I tend to lend them a thumbport for the first few weeks and they all end up buying one.

Another fan here. About 75% of my pupils use a thumbport. I've worn out one and am onto my second - the egde of the rubber coating eventually splits off into a dangly bit.

How odd! I bought one yesterday after struggling for a few months with my new flute - it's fully solid silver and has a b foot so is much heavier and I'm relatively slight so it was proving tricky in terms of balance and covering the holes properly with the right hand. Thumbports are absolutely brilliant

Thanks all, I will order one today!

What a brilliant idea! I wish those had been around 20 or so years ago when I was playing my flute and piccolo a lot. I used to put fabric plasters on my resin piccolo body to help with the slippage etc, but didn't dare put them on the silver plate of the flute!

It's not just slippage. Some of my pupils have short little fingers and struggle to reach the lowest keys. I have a very short thumb and when I put my fingers on all the keys in the correct position my thumb doesn't reach the flute.

One of my adult pupils has also bought a right hand grip. I was dubious about it's worth until I saw that the side effect is to place the hand further over and so align the fingers straighter to the keys. I'd certainly recommend that for adult beginners, especially older or less flexible ones.

Have ordered one and will give a progress report when ready!

It arrived very promptly today, (thank you Jonathan Myall's!) and I've been having a go.

It's light and unobtrusive and snaps on and off easily.
It was best for me placed between the middle of the E and F keys rather than directly under F.
It has definitely brought my fingers into a better playing position, my thumb stays put and the flute feels nice and stable.
At first the sound was slightly muffled but then I realised that as the keys are now sloping more away from me and the rods are higher up I need to turn the head joint in more and now there's no difference.
It's made an immediate difference to a couple of nightmare bars that I've been struggling with for weeks (fast triplets with lots of C-D changes) Worth it for that alone!
I hope I'll be able to improve clarity now as any gloopy sounds are due to sloppy fingers rather than the flute moving around.

Think it's a good buy!

Thanks for the report! I ordered one as well (after reading your thread - I'd never heard of it before) and will experiment with it tomorrow.

(Mine arrived in an absolutely massive padded envelope - my baffled postman thought there was nothing in it!)

I'll expect a detailed report!

Well, having used it solidly for about four weeks, I forgot to put it on the other day. When I realized, I had been playing comfortably in a good position and my thumb hadn't been slipping around. So it seems to have had a training function. I've decided to keep using it a few days on and then a day off, until I'm really sure I'm cured of bad habits! Very pleased with it.