10k Yellow Gold 0.6 mm Box Chain Necklace (16 24 inch) Overstock 10K Solid Yellow Gold Box Chain 10k Yellow Gold Classic Box Chain (0.45 mm) 10k Yellow Gold Box Chain 18" 10k Yellow Gold Box Chain 22" 100 Ways. 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