... optional);Current Draw: 12V/300mA; 24V/150mASuitable for: Wooden door, Glass door, Metal door, fireproof doorFinishes for Shell: Anodized aluminum & surface texture ... rating of contact current 3AAdvantage:Easy to install, no frame door can choose bracket to use;With dual voltage of 12V ... (reader, exit button, intercom);Easy to install, no frame door can choose bracket to use;With dual voltage of 12V ...