Some of them are two knockoff PlayStation 2 controllers sharing one USB lead while some others are USB adapters with two DualShock 2 (PS2 controller) ports internally, the part that talks to the computer is the same. This is the 64-bit driver setup for all DualShock 2 USB gamepads with a hardware ID starting with VID_0810&PID_0001, apparently manufactured by VIA Labs (aka VLI).
