changer
/ˈtʃeɪndʒə(r)/noun
1- a person or thing that changes something作改变的人（或物）。
1.1
- Computing a device that holds several disks, CDs, or other memory devices, and is able to switch between them【计算机】自动换片器：
a disk changer.
磁盘自动换片器。