The WT32i from Silicon Labs is a RF Module with Frequency 2.402 & 2.480 GHz, Supply Voltage 1.8 to 3.6V, Output Power 6.5 dBm, Sensitivity -90 dBm, Line of Sight Range 100 to 200 m (between two WT32is), 20-40 m to a smart phone. More details for WT32i can be seen below.