Amazon Music Unlimited offers 75 million tracks in lossless High Definition (HD) and millions more in Ultra High Definition (Ultra HD).
HD tracks are 16-bit audio, with a minimum sample rate of 44.1 kHz (16/44.1 is also referred to as CD-quality), and an average bitrate of 850 kbps.
Ultra HD tracks have a bit depth of 24 bits, with sample rates ranging from 44.1 kHz up to 192 kHz, and an average bitrate of 3730 kbps.