It is a modern instrument, a XIXth century evolution of the been, a traditional instrument of classical hindustani music.
From the been it has kept the flat bridge (jawari), the two pumpkin resonators (thumbas), a body, hollow tube made of teak wood on which the strings are fixed at both ends.
The playing strings tuned PA SA PA SA and the two sets of rhythm strings, the first tuned in the upper octave SA SA and the second in the middle octave NI SA SA.
The strings are stopped by a glass egg, a technique originating most probably from the playing of the tempura : this instrument (which is now only used to accompany singers), was used a long time ago by some musicians of the Gwalior gharana to play a melody, stopping the note with a wooden stick.
Because of the absence of frets, one can play perfect meends (glissandos) on a octave and a half, something difficult to perform on a been, and so get closer to the abilities of the human voice.

Multiple influences have added to the instrument sympathetic strings : the 15 strings are tuned on the notes of the raga from SA to PA.
Its actual shape has been claimed by a Patiala gharana musician : Abdul Aziz Khan.