In some Eastern traditions bangles were offered to the bride and groom rather than rings. The tinkling of jewelry, bangles and anklets as a woman moves about is an auditory reminder to her lover of her presence and is considered a part of their play.
All bangles are hand-forged. They are not hollow. Metals available are 14, 18, and 22 karat gold, and sterling silver. See examples of bangles and bracelets here.