SK4-R EM is of digital backlit, supports to read 125KHz EM cards. It is a metal case, Wiegand output keypad, with integrated proximity reader. Because its waterproof, it can be mounted either indoor or outdoor in harsh environments. Metal Case, anti-vandal. Waterproof, conform to IP66. Card Type: 125KHz EM Cards/Fobs. Wiegand Format: Wiegand 26 default (26~37 available upon request). Keypad Transmission: 4 bits (8bits or virtual card number format are available upon request) Reading range: 4 ~ 8 cm