Material: Stainless steel land alloy, it is hypo allergenic, it doesn't rust, change colour or tarnish and it is lead free and nickel free. Package: This keychain will arrive in a velvet bag ready for gift giving.Exquisite packaging, fast transportation, no need to worry about damage in the process of transportation. Size: This grandma's gift key chain is 1.2cm * 5cm. Please forgive me for the error in manual measurement. Mathematician Gift For Math Geeks Nerds Lovers! Engraved with the sentence "Inspire ". We only stamp on one side of the keychains! Mathematician Gift For Math Geeks Nerds Lovers!