Zkteco ZK X990-C Biometric Reader Its an innovative biometric fingerprint reader for time attendance applications, Supports optional backup battery, GPRS and Wi-Fi. Optional built-in 2000 mAh battery can eliminate the trouble of power failure. The X990-C features the fastest commercial-based fingerprint matching algorithm and ZK high-performance, high-image quality optical fingerprint sensor. The 3-inch TFT can display more information vividly, including fingerprint image quality and verification results etc. TCP/IP communication is standard and makes sure the data transmission between terminal and PC can be easily done within several seconds.