This is a high grade solid gold TITANIUM 6ALV-ELI (Grade 23) IMPLANT GRADE lip ring with a 2mm ball. The comfortable flat end measures 4mm. The size is 16 gauge or 18 gauge and 8mm-5/16, 10mm-3/8, or 12mm-1/2 of an inch. The 18 gauge labret is only available in 8mm-5/16" inch length. The entire piece is nickel free.