Amazon.com: Simpeak Bands Compatible with Galaxy Watch 3 45mm/Galaxy Watch 46mm/Gear S3 Classic Frontier, Solid Stainless Steel Metal Band with Standard 22mm Lug Width , Black
For Samsung's Gear S3, size matters. And that's a problem - CNET
Amazon.com: Samsung Gear S3 Frontier SM-R760 Smartwatch, International Version, No Warranty