Photo belong to Bangbangblond.
A fanny pack (American English) or bum bag (British English) is a small fabric pouch usually secured with a zipper and worn by use of a strap around the hips or waist. The American and British names derive from the fact that they are often worn with the pouch above the buttocks, for which "fanny" and "bum" are the slang terms in each country respectively, although they may also be worn with the pouch at the front. #wiki
Now here it is in fashion as the Belt bag.