Blastking MHU-IE4 Quad UHF Wireless In-Ear Monitor System
(4) UHF Antennas. Digital Signal Processor. Super Anti-Jamming Circuit Design. 100-240V AC Power Adapter. (4) Earphones with Carrying Case. Frequency Response: 50Hz ~ 15 KHz. Total Harmonic Distortion: < 0.5 %.