The DBu belt pack and DHu handheld transmitters include specially developed, high efficiency digital circuitry for extended operating time on two AA batteries and offers RF power selections at 25 and 50 mW. The pure digital architecture enables AES 256-CTR encryption for high-level security applications. Studio quality audio is assured by premium components in the preamp, wide-range input gain adjustment and DSP-controlled analog limiting. Input gain is adjustable over a 45 dB range in 1 dB steps to allow an exact match to the input signal level, maximizing the dynamic range and signal to noise ratio. USB ports on the transmitters allow for firmware updates in the field. Two-way IR ports ensure quick setup and allow for encryption key transfer and other data sharing between units. The D Squared System is built on Lectrsonics' 4th-generation digital architecture for excellent flexibility, ultra-fast setup, studio quality audio, and ultra-low latency. Features include 24 bit, 48 kHz digital audio, 2-way IR sync, three encryption modes, three receiver diversity choices, and a tuning range from 470-614 MHz.