Towallmark(TM) Steampunk Goth Alloy Dinosaur Skeleton Dead Tyrannosaurus T-Rex Charm Necklace (Black) Alloy Material: Alloy. Thickness of chain: Approx 0.3cm / 0.1 inch. Dinosaur skeleton size: Approx 19*7.5cm / 7.5*2.9 inch. Perimeter: Approx 56cm / 22.1 inch (this length doesnt contain the 6.5 cm extension chain). Adjustable and easy to wearing, fit for most people.