Iron Fans Keychain Gift for Iron Lover Proof Dimension of the pendent is 2.5cm(1 inch), diameter of the key ring is 3cm(1.27 inch). Great for gifts ideal for car or house keys! Arc reactor pattern Keychain, perfect gift for fans. Dimension of the pendent is 2.5cm(1 inch), diameter of the key ring is 3cm(1.26 inch). Great for gifts ideal for car or house keys! Although he may be gone, his influence lives in every one of us. Buy these keychains to show as a proof to others that Tony Stark has a Heart and your love for him is 3008.r.