The Sony Ericsson W595 is a Walkman phone, and is the successor to the Sony Ericsson W580.
[2] It was announced on July 22, 2008 alongside the Sony Ericsson S510, Sony Ericsson W302 and Sony Ericsson W902, with the W302 being the low-end, the W595 the mid-range and the W902 the high-end.
Accessing the battery and/or SIM card slot is not straight-forward.
There is a slight gap along the side of the cover, in which you slide a nail to carefully pry the cover off.
[4]