Lips
Start rounded, as for "uu". As you glide, the rounding relaxes to neutral. The diagram shows the rounded start.
The British "cure" vowel: glide from a rounded "uu" down to a weak "uh". No r sound at the end.
Example words: cure, tour, pure, sure, tourist

Start rounded, as for "uu". As you glide, the rounding relaxes to neutral. The diagram shows the rounded start.
Start high-back. Let it relax down and forward to the central "uh" position. The tip stays down: no curling.
Medium. The rounded "uu" start is the stronger part; the "uh" ending fades away gently.
Say "pure" in a mirror. Your lips should start round and finish loose and neutral, and the ending should carry no r colour. If you hear an r, you have switched to the American version.
Adding an r at the end (that is the American version), or splitting it into two beats instead of one smooth glide.
🔊 plays the app's native voice. 🎤 records you so you can play it back next to it. Your recording stays in your browser.