With this hold-up button installed, you"ll feel safer because you know that you can instantly and silently contact someone in the event of a robbery or other emergency. Constructed with gold, silver, and copper, this switch is manufactured for maximum conductivity so you know your distress signal will always be transmitted efficiently. The ridges molded into the housing help you identify the switch by feel, since you don"t want to tip off the robber that you"re looking for it. The switch is designed to last, with a housing that is impact- and corrosion-resistant. A flashing LED helps you locate the switch in your time of need. The switch requires a lithium battery (included), which will provide up to a year of battery life.