The Iron Strong Jewelry designed 45 lb weight plate necklace is made of solid sterling silver. The weight plate is 18mm diameter, about the size of a dime. The weight plate necklace comes in 18″ or 20″. 20 inches is the common length for a male. The 45 lb weight plate necklace is handmade in the USA. The back has space for optional engraving. Examples of the custom engraving is in photo gallery. Custom engraving $35, email Tina@IronStrongJewelry.com for more details.Care instructions for Weight Plate: To keep the black portions intact, do not use dips or immerse in water. Just use polishing cloth to clean tarnish.