Bolayu New Portable Alloy Nautical Compass Helm Keychain Ring Chain Gift Silver Zinc alloy, acrylic Material: Zinc alloy and acrylic. Made of solid alloy and acrylic, can bear long lasting use. Compass will work accurately if you lay it flat on flat ground. Sealed compass with helm shape. Creatively designed and fantastically crafted. Ring diameter: 3cm, Pendant Length: 6cm, Helm: 4.5x0.7cm (D x T).