BK AN 301 Dipole Antenna (0.8 to 1GHz) for model 2650/2658. It is possible to measure the electric field strength by connecting one of the optional dipole antennas to the input connector. Dipole antennas that suit many uses are available. AN 301 is mainly for PDC 800MHz and GSM 900MHz bands, AN 302 is mainly for PDC 1500MHz bands, AN 303 is mainly for PHS, W-CDMA and GSM 1800/1900MHz bands, and AN 304 is mainly for 2.4GHz wireless LAN and Bluetooth bands. AN 305 is for 390MHz to 410MHz. AN 306 is for applications between 4.7GHz to 6.2GHz (802.11a & GPS).