today you are going to add the missing fire-extinguisher.
It is positioned on the hull on the right side between the air intake/outlet.

It is missing on the HL.

You can buy it from different suppliers.
Get one and glue it.

Greetings
Birger
For a lot more help with your Heng Long Tiger I tank, follow the below link ...
http://www.rctankwarfare.co.uk/forums/v ... 18&t=11459