Debra Audio AU400 4 channel wireless microphone system. (Two set freuqncy point: A- 501/511.5/524/538.5 B-506/517.5/531/546.5). There series products adopt UHF frequency and use the international standard common frequency which can be used in all over the world. Due to the low frequency and many reasons, traditional wireless microphone usually disturbed by many factors especially by […]... Read More