HP ProBook 4320s, 4321s, 4420s, and 4421s Notebook PC
Bottom components
Component Description
(1) Battery release latches (2) Release the battery from the battery bay.
(2) Battery bay Holds the battery.
(3) SIM slot (select models only) Contains a wireless subscriber identity module (SIM). The SIM
slot is located inside the battery bay.
18 Chapter 2 External component identification