This 2-stack channel & diamond square ring set is rigid, yet extremely comfortable due to its softly rounded edges. This stack is made up of two rings including 1 thick (6mm) channel square ring with a 1.5mm diamond and 1 thick (2.5mm) silver square ring. This stack is available in sizes 5.0-9.5, including half sizes. Special note: Because of the width of our stack ring sets, it is recommended to buy a stack that is approximately a half to a full size larger than your normal ring size. Materials: Sterling silver (.925), oxidized sterling silver, and a lab-created diamond. All materials are hypoallergenic. We hand carved and oxidized the channel where the diamond is set. The oxidation is protected within the channel and is therefore better preserved over time. We love how the diamond really pops against the oxidized channel. This ring set was designed in San Francisco and is handmade in our Upstate New York production studio.