Surface Book's feature is the ability for the detach screen and become a fully-functional tablet. Surface Book model starts at $1,499, and gets you the detachable screen and the Surface Pen stylus. The Surface Book with dedicated graphics in the base starts at $1,899, and the top-of-the-line Performance Base models start at $2,400.
The Surface Book actually sports two batteries: One in the tablet portion, and one in the keyboard base.
Screen Size: 13.5 inches
Max Screen Resolution: 3000*2000 pixels
Processor: 2.1 GHz Core M Family
RAM: 8 GB DDR3
Hard Drive: 128GB/256GB/1T
Graphics: Coprocessor Intel HD
Number of USB: 3.0 Ports 2
Brand Name: Microsoft
Operating System: Windows 10 Pro
Weight: 3.5 pounds
Dimensions: 10.9 x 16.5 x 1.9 inches
Batteries: 1 Lithium ion batteries required.