Some Surface keyboards have a built-in trackpad.

Microsoft's Surface tablet offers a choice of detachable physical keyboards; connecting one allows you to type on your tablet in the same way that you would on a laptop or desktop computer, rather than typing directly on the screen. Surface keyboards are attached to the device itself using magnetic connectors. Once attached, the device will automatically recognize that a keyboard is connected and transfer control of typing functions over to that keyboard.

Attaching a Keyboard

To attach a keyboard peripheral to your Surface, simply snap the magnetic contacts on the keyboard to the corresponding contacts on the bottom of the Surface. All the keyboard's contacts must touch against the Surface's contacts for the keyboard to work correctly. If the Surface does not recognize the keyboard, try disconnecting and reconnecting the devices. If this still does not work, disconnect the two devices and rub both sets of contacts with a lint-free cloth before re-testing.