plastic can..my seg also plastic..very effective..immediately u can c the effect..erm..as wat hikaru mentioned..he say the light will become yellow soon after polised..i think it will become yellow but not so soon..at least can last for few months la..hehe! i polised it for almost 1month+..still ok..the autosol just rm9..i think can polish the light for more than 10 times..so it is worth also... :D :P