The Princess cut Hybrid Curved Barbell is 6mm and set into a 14K Gold setting permanently attached to a Implant Grade 316LVM Surgical Steel Curved Barbell. The Top Gem is a 3mm Round Gem and the setting is also made out of 14k Gold. These two metals fuse well together for a very solid piece. These curved barbells are also internally threaded for your comfort and can be made in either 14K White or Yellow Gold.