... years warranty,one year free exchange for quality!HUA Contact Button HUA-90AType:1990A-TM Button,global unique ID(unmodifiable)Physical: ... water-resistant.strong & durable.Used as patrolman identification.1. Ideal for Security Personnel, monitoring Factories, Offices, Hotels, Car parks, Shopping ... issue, Inventory, Asset tracking etc... Personnel ibutton/metal ibutton for access control management