(Size 9) Waterproof Ceramic NFC Ring R4 Smart Ring Wearable IP68 For|

R4 can quickly trigger multiple preset notifications on any phone. No need to install an app for direct use, and suitable for both for and for IOS platforms. Protection Level: IP68. Ceramic Material: The R4 ring is made of microcrystalline zirconium ceramics, with excellent refractive index and dispersion performance, giving off a unique round luster overall.

eBay