Sea Siren - Mermaid and Peace Turtle Saddle Ring - Rainbow Moonstone and Blue Topaz - Will fit like a Size 10Homeward Bound Nautical Collection Sea Siren and Turtle Ring DETAILS: Mermaid Siren Ring with peace turtle Sterling Silver Rainbow Moonstone and London Blue Topaz Size: 10 This ring measures just over a 10. 5 on a ring mandrel, and may fit and feel smaller than the mandrel size depending on your knuckle and with finger swelling. Back of ring shank measures 7. 5mm wide for reference. A little info regarding the fit of saddle style rings: Saddle rings