The classic Boa Chain, made for those who are driven by purpose and the relentless pursuit of their dreams. Crafted from high-quality surgical-grade 316L stainless steel, this chain embodies both strength and style.Featuring a waterproof design, you can confidently wear it in the sea, pool, or shower, while its heat and sweat-resistant properties make it ideal for workouts. Size: One size. 50cm + 2cm extension (20" + 1") - Fits more than 95% of our customers. Most prefer this size. Chain thickness: 6mm