The lock housing is made with aluminum,it is made by ourseal company,OURSEAL(R) is a famous brand of security seals in China,it is a creater of ISO17712.there are more on the ourseal's official web site.OURSEAL also produce high securit bolt seals compliant with ISO17712:2013,meter seals,plastic seals,cable seal,waterproof security bags and so on. you are welcome to cooperate with us at anytime.