KaShDa Multi-Ring 14MM Gold Plated Toggle Bar Necklace Extenders 1 to 5 Rings - 1 5/8" to 5 1/8" - Nickel Free One extender that can let you adjust the length of your necklace to the desired length. 14MM (about 1/2") Gold Plated Zinc Ring and Bar. The ring has a hole size of 11MM (just under 1/2"). The bar is 19MM (3/4") long. See IMPORTANT SIZE INFO below. 3.5MM Gold Plated Brass Core Curb Chain, just enough to allow easy insertion of the bar. The shorter sizes can be used on a bracelet or use a longer one as a bracelet.