Amazon, here are some i found if you want
Kingray Jewelry Two-Pack, 3mm Black White Polished Ceramic Wedding Band Stackable Ring Enhancer https://www.amazon.com/dp/B07JPB3C8G/ref=cm_sw_r_cp_api_i_QN5Y3SXCBWARS5P0CFJZ?_encoding=UTF8&psc=1
MJ Metals Jewelry Ceramic Wedding Band Classic High Polished Ring Varying Colors and Widths to Choose from https://www.amazon.com/dp/B01N28AJ9G/ref=cm_sw_r_cp_api_i_YJ03B0FFZXNVCZMVXTC3?_encoding=UTF8&psc=1