The Bible teaches that when you are married, you are become one flesh. "Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh" (Genesis 2:24).
The words, "And they shall be one flesh" is engraved on the front of a 14k white gold wedding band ring, with your names and wedding date (or inscription of your choice) engraved on the inside of the band.
The ring is available in 6mm - 8mm width (shown here in 6mm).
Also available in 18k or yellow gold (shown below).