Pigtails and Electrical Drawings

Pigtails http://electrical.about.com/od/wiringcircuitry/ht/pigtailwireconn.htm

I suggest you google you other subjects for an answer.

25x3 is the width and thickness of the copper earthing flat.

25x3 represent the width and thickness of the copper flat being used for earthing.

Pig tail is the terminal end of the earth conductor

air terminal base is the lightning protection or earthing rod base

oblong test point is the isolation point for testing

earth inspection chamber is the location where a earth rod and earth flat get terminated with certain clamps, which can be inspected for proper jointing and for testing isolation.

All the above are the accessories of earthing system.