Love her voice! Well in case you don't know what you are getting, you are getting a cd with 3 songs: Liar mask, liar mask instrumental, and (idk its english name) 蜃気楼. And you'll also get a DVD featuring LIar mask's Music video and its production process. All in japanese though, no English sub.
Overall I love Akame ga kill and this is my favorite song from the anime so I think this is a must get!