Buying an Auto Level
Buying an Auto Level as asked with vendors is very simple, we need to know how much optical zoom we want and the company of choice.
Yes its that simple.
Auto Level comes with Shaft (Meteric or Architectural Units) and with small manual.
It is necessary to read manual carefully to know how to find the horizontal distance by noting stadia readings and its unit of multiplication.
Manual also explains how to measure shaft on the field.