A clapper is attached to the inside and the bell makes a high pitched sound when rung.
[1] In Hinduism, the mantra chanted while ringing the bell is[4] Aagamaardhamtu devaanaam gamanaardhamtu rakshasaam, Kuru ghantaaravam krutva devataahvaana lanchanam
From the Kundalini Yoga perspective, the sound of a bell energizes chakras and balances the distribution of energy in body.
In Shilpa Shastras it is mentioned that bell should be made of panchadhatu – five metals, namely, copper, silver, gold, zinc and iron.
The handle of the bell represents Prana Shakti – vital power and is symbolically linked to Hanuman, Garuda, Nandi (bull) or Sudarshana Chakra.