... service 4.use for light tube 5.any color is ok *PRODUCT DETAILS ST-366 LIGHT TUBE BUCKLES1) Materialiron2) ... ColorsNickel/nickel free, anti-brass, anti-copper, gun metal, light pewter, dull- ... nickel, nickel free dark pewter, nickel free light pewter, nickel free dull-nickel, and more3) ... eco-friendly materialPassed SGS test metal Light tube buckle