Crafted from high-quality nylon resin, this cage offers a lightweight and durable construction, ensuring long-lasting comfort during wear. The Pink Cobra Chastity Cage is available in five different sizes, catering to a wide range of body types. Each size comes with a variety of ring options, ensuring the perfect fit for everyone. Store link: Pink Cobra Chastity Cage – MChastity
The flat ring version has 5 rings: 43mm(1.69"), 46mm(1.81"), 49mm(1.93"), 51mm(2.00"), 55mm(2.16"), the largest is 2.16"
The real Kink3d Cobra has rings up to that size and I would recommend it over this knockoff: https://kink3d.com/pages/size-guide-base-rings