The IFBlue receiver provides simplicity and flexibility in a tough package that is intuitive for untrained users to operate. In spite of its small size, the receiver pack offers excellent performance and convenience. The dock charging feature and supplied rechargeable batteries make daily use a snap, while 10 programmable preset frequencies give you excellent flexibility on set or in the studio. The IFBlue receiver pack is offered in five different frequency ranges to match existing T4 transmitters: VHF (174-216 MHz), A1 (470-537 MHz), B1 (537-614 MHz), C1 (614-692 MHz) and 941 (941-960 MHz).Transmitters available from Lectrosonics include the IFBT4, IFBT4-VHF, or any Digital Hybrid Wireless transmitter in IFB compatibility mode.