Specifications: Bluetooth:16-32Bit/44.1k-96kHz;  Bluetooth format:SBC/ AAC/aptX/aptXs LL/ aptXs HD/ LDAC;  Gain:+3/9dB;  S/N:115dB;  Crosstalk:≥75dB;  Charging time:about 3 hours;  Size:105 x 55 x 15.6mm;  Weight:142g;  Sampling rate:USB PCM: 16-32Bit/44.1k-384kHz; DXD: 34-32Bit/352.8kHz; DSD: DoP/NATIVE mode, DSD64-256;  Frequency response:USB/Bluetooth: 20Hz-20kHz(±0.5dB); AUX: 10Hz-100kHz(±0.5dB);  Output power:300mWat32ohm;  Computer USB input:support Win7/8/10, iOS, Android system;  Battery:3.7V/1.800mAh;  THD+N:USB:0.001%at1kHz; Bluetooth: 0.002% at 1kHz; AUX IN: 0.0009% at1kHz;     Features: Professional power amplifier circuit, powerful output power.  Different from the traditional integrated amplifying circuit, XP-2Pro applies the brand-new OP+BUF circuit structure, bring more thrust. The amplifier output power is enhanced to 300mW   300mW output power Under the 32ohm load, the output power is up to 300mW, solve that your headphones can’t drive well enough, so as to drive your headphone to a new level.  DAC chip adopts ES9018K2M chip, shows excellent performance, and supports native DSD, DXD and PCM signals. The maximum support is PCM-32Bit/384kHz, DSD256, and DXD 32Bit/352.8kHz.  Qualcomms Bluetooth chip CSR8675 Qualcomms flagship Bluetooth chip CSR8675 supports Bluetooth 5.0 version and supports SBC/AAC/APTX/APTX LL and LDAC high-definition audio format transmission.  Built-in microphone with Qualcomms cVc noise cancellation technology The built-in customized audio microphone with high sensitivity supports Bluetooth voice communication. Matching with the new generation of Qualcomms cVc8.0 noise reduction technology, it is clearer in communication to chat like a cork and you won’t pull out the mobile in a hurry to feel awkward.     *Note: the built-in microphone is only available under Bluetooth voice communication, instead of a mobile voice assistant.  Simple one-touch NFC pairing.  With the NFC function, after it contacts the equipment with the NFC function, it can recognize and easily link with it. You won’t be bothered by a fussy setting.  Asynchronous USB DAC.  Note: it needs Apple’s official original camera USB.  Multi-color indicator.  The change of each color represents different coding formats.     Under the Bluetooth mode: SBC:blue light;  AAC:green light;  LDAC:white light;  aptX/aptX LL:purple light;     Notes:  1. When the battery power is less than 20%, the orange lamp is always on.  2. Under the charging mode, the red light is always on; after it is fully charged, the green light is always on.  Battery life:USB IN≥8H, AUX-IN≥22H, Bluetooth≥15H;  Charging time:≤3H;  New appearance technology: Adopts high-strength aluminum alloy. Matched with high-hard 2.5D tempered glass technology, and the red volume button is matched with a deep grey body to show personality in calmness.     Package Included:  1 x Headphone Amplifier