For your info:
I connect the plug extension to the tip of the plug (at the engine block) and the other end to the glow starter. Is this correct? Tawdawson mentioned about grounding. Should there be any grounding. Cos there 2 types of plug extension they gave me.

1) Clip and 'Plug' extension
2) Washer type extension (Is this for grounding? I doubt so.)

I understand that i can use either one, right?