Unknown Custom is a budget custom IEM company from Malaysia. They operate mostly from Facebook, (https://www.facebook.com/UCCIEM/). The current flagship, Quad 2.0 is a 4BA with 3-way passive crossover design.
IMPEDANCE: 26 Ohms@1kHz
ISOLATION: Up to -26dB
DRIVERS :4 BA per side / 2 high, 1 mid, 1 low
CROSSOVER: UC 3-way passive crossover design
HiFi Bluetooth Receiver with aptX/aptXHD/aptXLL/LDAC/AAC Support; Portable Mini Music Audio Receiver for Home TV, Speakers, and Car Stereos; NFC...
Immaculate Dynamic Sound Reproduction and Spectacle Sound Stage with Brass Chamber
Ausdom ANC7 Active Noise Cancelling Wireless Bluetooth Headphone
Active noise cancelling with AptX technology and Bluetooth V4.0.