It's 24/96 if they say it is. If you have Amazon Music HD, some music is available in 16/44 and some is available in higher bitrates/bitdepths (I've seen 24/44.1, 24/96, and 24/192).
I bought one of these to test a couple pairs of speakers I built. If I'd messed up, I didn't want to destroy my more expensive amplifier. For that, it worked fine--music came out of the speakers loud enough to verify that I didn't make any mistakes.