Each C-shape bangle is made from a gold strip, the first a Liao dynasty example, ending in two dragon heads, the exterior incised with floral scrolls against a dense ground of small punched circles; the second a Ming dynasty example decorated with a single raised ridge centered with a floral blossom, two terminals carved and chased with leaves.
Note:
Similar Liao dynasty bracelets, see YANG, Boda. Zhongguo Jinyin Boli Falangqi Quanji, volume 2. Shijiazhuang: Hebei Fine Art Press, 2004, page 183, fig. 328-329.
LIN, Yeqiang. Celestial Creations, Art of the Chinese Goldsmith, The Cheng Xun Tang Collection I. Hong Kong: The Chinese University of Hong Kong, 2007, pages 254-255, E09. 
SUN, JI, and GUAN, Shanming. Chinese Gold Ornaments. Hong Kong: Mu wen tang, 2003, p 382-383

A Ming dynasty bracelet with a similar 'central ridge' motif, see LIN, Yeqiang. Celestial Creations, Art of the Chinese Goldsmith, The Cheng Xun Tang Collection II. Hong Kong: The Chinese University of Hong Kong, 2007, pages 472-473, G73.

類似遼代手鐲，參見内蒙古巴林左旗契丹博物館藏龍首鸞鳥紋金鐲；楊伯達主編《中國金銀玻璃琺瑯彩全集》第二卷，河北美術出版社2004年出版，第183頁，圖版328-329；林業強主編《寶蘊迎祥：承訓堂藏金I》，2007年香港中文大學中國文化研究所文物館，第254-255頁，E09; 孫機，關善明合著《中國古代金飾》，2003年香港沐文堂美術出版社有限公司，第382-383頁。

類似帶凸弦紋與花卉紋飾的金鐲，元-明皆有，參見博爾塔拉蒙古自治州博物館所藏，達勒特古城出土的元代金鐲以及銅鎏金手鐲，和林業強主編《寶蘊迎祥：承訓堂藏金II》，2007年香港中文大學中國文化研究所文物館，第472-473頁，G73。