"10K Real Yellow Gold 0.45mm 0.6mm Elegant Box Chain Necklace with 10k Yellow Gold Box Chain 22" 100 Ways 10k Yellow Gold Box Chain 18" 10K White Gold 0.45mm Box Chain with Lobster Clasp 18 Inch. This classic box chain comes in 10k yellow gold and has a width of 0. 45 millimeters. Product Details: Chain Information : Metal : 10K Yellow Gold Chain Type : Box Clasp : Spring Ring Width : 0. 45 mm Approximate Weight: Size Weight 16'' 0. 6 grams 18'' 0. 75 grams 20'' 0. 8 grams