BW0029AG-L3.5W1.5H1.6 with SMD,3.5x1.5x1.6mm Contacts / Springs ROHS is a surface mount device (SMD) manufactured by BAT Wireless that measures 3.5x1.5x1.6mm. It has contacts and springs that comply with the Restriction of Hazardous Substances (RoHS) directive. It is a relatively small device and is typically used for communication and data transfer applications such as WiFi, Bluetooth, and near-field communication (NFC).