The UltraSoundGate from our cooperation partner Avisoft Bioacoustics is the ultrasound interface of the BATmode system. It converts the analogue signal from the microphone into a digital signal and transmits it to the BATmode via USB. The UltraSoundGate is available in several variants - 116Hbnm, 116Hnbbm, 116Hnbm-r, 116Hnbbm-r and 416Hnbm. A direct comparison of the UltraSoundGate variants can be found in the table below. All "116" variants have one microphone channel, while the UltraSoundGate 416Hnbm has four microphone channels. This means a BATmode system can be equipped with up to four UltraSoundGates 116 or one UltraSoundGate 416Hnbm. The UltraSoundGates also serve as hardware licence dongles for the Avisoft-RECORDER recording software. If several measurement channels are used, the cheaper UltraSoundGates 116Hnbm-r or 116Hnbbm-r can be used, which do not include a licence. In addition to the UltraSoundGates 116Hnbm, 116Hnbm-r and 416Hnbm, which are compatible with Probat and the RENEBAT projects, UltraSoundGates are also available for combined bat and bird detection. In contrast to the bat-only UltraSoundGates, these have a cut-off frequency of 100Hz instead of a lower cut-off frequency of 1 kHz.