Linsoul
Linsoul SIMGOT DEW4X Portable in-Ear Monitor Amplifier, HiFi Earphone Stereo USB DAC with Dual CS43131 DAC Chip, 384 kHz/32 bit, Tiny Audio Amps for PC/Phone (DEW4X)
Dpofirs
in-Ear Monitor Headphone Amplifier for Drummers Keyboardist Guitar Player Vocalist Bass Player, Stereo Headphone Earphone Amp Volume Control with XLR
JINGHAO
JINGHAO Hearing Amplifiers Aids Rechargeable with USB Charger Case Sound Amplifier Pair for Seniors, in The Ear Hearing Assis, Looks Like Earbuds, Black
Behringer
Behringer POWERPLAY P2 Ultra-Compact Personal in-Ear Monitor Amplifier