14K Gold Filled Stacking Rings Handmade, size to order. These 14K 14/20 Gold filled Twisted design "Skinny" stacking rings are 1.3mm thick(16 gauge) Tumble hardened and polished to a bright finish. Buy multiple units at a discounted price. Four bands is approximately 5mm thick. Polishing cloth and ring sizer included. Ships in gift box. Gold filled "14/20" refers to the industry shorthand describing the resulting material. The first number is the karat purity of the gold used; the second number is the amount, by weight, of gold to the substrate material. "14/20" gold-filled material is made with 14-karat gold and the gold represents 1/20th (or 5%) of the total weight of the material.