Microphone
From Amazon
Chord | Replacement Wireless Microphone For The NU4 | 864.8MHz | Red
Inta Audio
Chord Replacement NU4 Handheld Microphone - Yellow 863.1MHz
CommsAndSound
Chord Nu4-ht863.1 Nu4 Handheld Microphone Transmitter Yellow 863.1mhz
Gear 4 Music
Chord NU4 Handheld Microphone Transmitter, 863.1MHz, Yellow