12k Gold and Sterling Silver 925 Twisted Rope Ladies 22.6g
My Internet research tells me 12k Gold is seldom used these days which helps in dating this piece. 12k gold is a gold alloy just as any other alloy, with 50% gold and 50% other metals. 
12k i.e. 50% gold was used in the past, and sometimes also today (although rarely) because alloyed with 50% silver it turns a strange greenish color.
Item Description:
Nice smooth bracelet that has twisted silver with a 12k gold filled middle section.
Excellent vintage condition consistent with age and moderate use.
The cuff is boldly stamped at one end "1/20 12K GF" and TA at the other end which could be the silversmith?  If there is more to the mark, it has been smoothed out from use.
The piece is somewhat adjustable with the space between ends of 1 and 3/4 Inches.  The interior is 5 Inches so a 6 and 3/4 Inch wrist should work well.  The width is 1/2 Inch.
Worldwide destinations, please message me to adjust rate quoted at $25.00.