Metal Type: Titanium Metal Color: Silver Necklace Style: Heart, Key Pendant Size: 3.0x2.6 cm(couple) Net Weight (g): 15g (Male And Female Necklaces)Titanium has become popular as a jewelry material due to its various unique properties. Titanium rings offer several unique properties: they are biocompatible (hypoallergenic), lightweight, corrosion-resistant, and have the highest strength-to-weight ratio of any crystalline metal. Titanium rings are therefore practical jewelry for those who regularly swim in the ocean or chlorinated pools. Similarly, titanium rings will not react with wearers who suffer allergies to other jewelry materials.