... concealed,waterproof 5 years warranty,one year free exchange for quality!HUA Contact Button HUA-90AType:1990A-TM Button, ... ,water-resistant.strong & durable.Used as patrolman identification.1. Ideal for Security Personnel, monitoring Factories, Offices, Hotels, Car parks, Shopping centers, ... Goods issue, Inventory, Asset tracking etc... Personnel ibutton/metal ibutton for access control management