Mens Signet Ring Vintage 10K/ Sterling “R” Initial Art Deco Man Ring Size 9. Offered here is old, vintage men’s Art Deco design letter “R” initial signet ring. The floating 10K “R” contrasts perfectly over the black onyx and 10K top portion. Measures about 5/8 wide and tapers to 4 mm. Was sized, somewhat crudely, but effectively.