What is "tonbak"

The Tompak (official Persian name) (تنپک, تنبک, دنبک، تمپک), also tombak, donbak, dombak or zarb (ضَرب or ضرب) is a goblet drum from Persia (ancient Iran). It is considered the principal percussion instrument of Persian music. The tonbak is normally positioned diagonally across the torso while the player uses one or more fingers and/or the palm(s) of the hand(s) on the drumhead, often (for a ringing timbre) near the drumhead's edge. Sometimes tonbak players wear metal finger rings for an extra-percussive "click" on the drum's shell. Tonbak virtuosi perform solos lasting ten minutes or more. The tompak had been used to create a goblet drum.