Merkabah is commonly known as a "Lightbody": a chariot or vehicle that is used for inter-dimensional travel by Masters and Spiritual seekers. To some it appears as a 3-dimensional star tetrahedron (a 3D version of the Star of David). It is said to be used to transport the spirit-body from one dimension to another.

Merkabah is not an invention of the New Age movement. It is a real technique that has been taught in various religious and spiritual disciplines since ancient times. We can see and understand the accounts of its existence in many ancient texts, including the New Testament of the Bible. 

A fully activated Merkaba looks just like the structure of a galaxy or a UFO.