The packaging is blister, it only contains the amplifier and its power supply, so an extra cable will be needed.
It has one 6.3mm and RCA L,R inputs.
The outputs are 4 6.3mm ports, which can play headphones with a 3.5mm jack confirmed with an adapter, provided the user has an adapter.
It also has a switch button from stereo to mono.
I use it on my computer's sound card as a headphone splitter, so when we gather together, we can listen better without disturbing.
The sound on 300Ω Nominal Impedance headphones is powerful without distortion and without compromising the sound quality from the card, nor the volume, so there is no need to activate the card's preamplification.
I think there is nothing else to mention since the machine is very simple and for a specific use.