The transcription of the Georgian letter u is u.
'u' is pronounced almost like English [u] in 'book' or 'full'.

Recordings:
 
 

When pronouncing the vowel 'u' the tip of the tongue is  slightly retracted from the lower front teeth. The bulk of the tongue is raised and is close to the soft palate. There is a resonance area of considerable size in the pharynx area.

The letter written or typed in this way is called uni.

It is traced out with one movement of the hand and is written between the three lower lines: movement of the hand begins from the upper middle line, goes a bit downwards and from left to right draws two small semicircles in a wavy line resembling the Latin letter 's' lying on the side, continues upwards in a semicircle and goes downwards vertically, drawing one more semicircle from right to left at the lower line and ends with a slightly rounded tip to the right between the lower middle line and the lower line.