The ACS ACR3901U-S1 card reader is a wireless contact smart card reader with Bluetooth capabilities, featuring USB connectivity, making it ideal for flexible use with mobile devices and computers. It supports Bluetooth Low Energy/Bluetooth 4.0 and USB CCID via micro-USB, and comes with a rechargeable lithium battery that is charged through USB.

The reader supports ISO 7816 Class A, B, C contact smart cards, T=0 and T=1 protocols, and most memory cards available on the market. Reading/writing speeds reach up to 600 Kbps, and it offers AES-128 encryption as well as firmware upgrade capability in the field.

Compatible operating systems include Android 4.3 and above, iOS 8.0 and above, Windows, Linux, Mac OS, and many desktop/server editions of Windows in PC-linked mode.

The compact unit measures 94.00 x 60.00 x 12.00 mm and weighs 30.8 g (59.7 g with cable) and includes a removable 1 m cable. The compliance standards include EN/IEC 60950, ISO 7816, PC/SC, CCID, CE, FCC, RoHS, and Microsoft WHQL.