A Victorian "gas pipe" bangle or bracelet is a flexible, hollow tubular gold piece named for its resemblance to industrial gas pipes of the 19th and early 20th centuries
 
It features interlocking or tightly coiled metal strips that create a flexible, ribbed, and spring-like tubular band.
 
While true welded-Tubogas became famous later during the Retro and Mid-Century eras (popularized by brands like Bulgari), the flexible coiled-band style traces its industrial inspiration back to late-Victorian and Edwardian flexible mesh or expandable snake and pipe designs.
 
Clips open and closed securely with a clasp which has a hallmark but I can't decipher it. Has a silver safety chain for extra security.
 
weighs - 33.3g
diameter of coil - 12.3mm
inner diameter - about 61mm
wearable inner circumference - about 7"
 
Condition - excellent