DualShock, PlayStation 2 Expansion Bay
PS2's controller is largely identical to the PSX game pad, with the same basic functionality; however, it includes analog pressure sensitivity on the face and shoulder buttons, is lighter and includes two more levels of vibration. The fact that the design didn't change pleased some consumers who were already used to the PS1 controller, however, it disappointed others who were hoping for a more ergonomic design. To fix this many 3rd party producers are making analof joysticks for PS2 in all shapes and sizes including Arcade / retro looking controllers.
PS2 Optional hardware includes additional controllers, a DVD remote control, a hard drive (PS2 HDD), a combination modem and Ethernet adapter (LAN), memory cards, and various cables and interconnects: Multitaps, Component video, S-Video, VHF antenna video cables, webcam (AKA "EyeToy"), keyboard, mouse and Headset.