From the seller:

Designed to work seamlessly with PreSonus’ StudioLive Series III family of mixers, yet compatible with other AVB-enabled systems, the PreSonus EarMix™ 16M personal monitor mixer accepts 16 mono channels of input via AVB networking. An aux input admits an external source to the local mix. You get stereo channel linking and channel grouping, along with three-band EQ and limiting for each channel and the main mix, balanced ¼-inch TRS L/R outputs, and a loud, clear headphone amplifier that can drive low impedance devices such as high quality in-ear-monitors. Two AVB jacks enable daisy chaining; network up to 24 units with a StudioLive Series III mixer. The EarMix 16M can be powered from the included external power supply or over Ethernet (PoE) from a compatible switch. Features: - PRESONUS EarMix 16M 16x2 16-Channel AVB Personal In-Ear Monitor/Headphone Mixer - 16x2 AVB-networked personal monitor mixer - Loud, clear headphone amp that can drive low-impedance in-ear monitors - 3-band EQ and limiter on all channels and main mix - Stereo channel linking and channel grouping - Support for PoE power - 2 AVB Ethernet ports; network up to 24 units with a StudioLive Series III mixer - 2 Balanced ¼-inch TRS line outputs 1/8-inch stereo aux input - Store up to 16 mix scenes locally - Signal present and clip LED for each input plus 8-segment stereo output meter - 24 bit, up to 48 kHz operation - Routing setup from StudioLive Series III consoles and UC Surface Mic stand mounting option (sold separately) What's in Box: - 16x2 AVB-networked personal monitor mixer - Loud, clear headphone amp that can drive low-impedance in-ear monitors - 3-band EQ and limiter on all channels and main mix - Stereo channel linking and channel grouping - Support for PoE power - 2 AVB Ethernet ports; network up to 24 units with a StudioLive Series III mixer