This part is a kind of semiconductor called RN42.

Function of this product has Class 2 Bluetooth Module.

Manufacturers : Microchip

Image and pinout :

Some of the text within the PDF file :

RN42/RN42N Class 2 Bluetooth® Module with EDR Support Features • Fully qualified Bluetooth® version 2.1 module, supports version 2.1 + Enhanced Data Rate (EDR) • ASCII command interface over UART • Postage-stamp-sized form factor: - RN42: 13.4 x 25.8 x 2.4 mm - RN42N: 13.4 x 20.5 x 2.4 mm • Low-power (26 A sleep, 3 mA connected, 30 mA transmit) • UART (SPP or HCI) and USB (HCI only) data connection interfaces • Sustained SPP data rates: 240 Kbps (Slave mode), 300 Kbps (Master mode) • HCI data rates: 1.5 Mbps sustained, 3.0 Mbps burst in HCI mode • Embedded Bluetooth stack profiles include: GAP, SDP, RFCOMM, L2CAP protocols, with SPP, HID, and DUN profile support (does not require any host stack). • Bluetooth SIG qualified, end product listing • Castellated SMT pa [ ... ]

RN42 PDF Datasheet Download