https://www.lego.com/en-us/product/power-functions-motor-set-8293 

Bring your LEGO® Technic models to life with the exciting Power Functions Motor Set. This supplementary power set comes with a medium motor, battery box, switch and a light cable with 2 bright LEDs. Power up your LEGO Technic creations!

Power up LEGO Technic creations

Includes a medium motor, battery box, switch and a light cable with 2 bright LEDs
Switch and cable measures over 9” long. Switch (including orange switch) measures over 1” long and 1’ high and 1” wide. Battery measure of 2” high, 3” wide and 1” deep. M-Motor measure over 1” wide and under 1” high and 1” deep. M-Motor and cable measure over 10” long. Light cable measures over 15” long
LEGO Technic Power Functions Motor Set works with all power function compatible LEGO building toys for creative building 
10 pieces – For boys and girls between the ages of 9 and 16

$60 value.

This first volume of The LEGO Power Functions Idea Book, Machines and Mechanisms, showcases small projects to build with LEGO Technic gears, motors, gadgets, and other moving elements. You'll find hundreds of clever, buildable mechanisms, each one demonstrating a key building technique or mechanical principle.You'll learn to build sliding doors, grasping claws, rack-and-pinion mechanisms, and ball-shooting devices of every sort!

Each model includes a list of required parts and colorful photographs that guide you through the build without the need for step-by-step instructions. As you build, you'll explore the principles of simple machines, gear systems, power translation, and more.