Hexagonal nut is a metal fastener with six sides. Most nuts are cut into hexagons, because hexagons seem to be the easiest shape to grasp. Nuts of any form are almost always used to fix a bolt to another object.
Lithium-ion battery technology is the most popular technology in the battery field. Today, they are common power sources for several everyday products, such as laptops, cell phones, power tools, and even cars.