Nobsound Little Bear B4-X Valve Tube Dual-Mono Balanced Portable Headphone Amplifier HiFi(B4-X dual-mono balanced version)

Features Mini size and unique design: built-in tube makes you have a tube amplifier which can be held by one hand, convenient to carry and can enjoy HiFi music everywhere. With built-in battery protection circuit: battery lets your listening feast without time limitation. It can't be turned on during charging and will power off automatically after fully charged, and charger LED will turn to gre...