Installing twin tone horn

I know it is banned in city limits but I intend to install a secondary horn like the one attached is the pic. It is a pressure horn usually used for overtaking larger vehicle who have blind spots, during blind turns on the Ghats , asking for giving way while  overtaking  etc.. well this is not as loud as the truck horn but it is a twin sounding horn..

i am unable to attach pics....

Please guide me on what precautions I need to take? Do you think it would be safe to have a secondary horn as an extra fitment which would have a separate switch to use? I have a 55DN Amaron Flo battery and the extra load that it might gets is of the 100/90 lamps that I use for driving, with a relay in place.

Your thoughts please ….

If you have not changed your original horn (they are twin tone), you will not need an additional one.
The Logan has quite a decent horn whcih we refer in automotive language as "Severe Condition" horn. Specific to our weather / Abuse / Traffic condition.

Vsuprak, thanks, but I have not at all changed my original horn and I do not intend to do that. All I wanted a twin tone horn was for use on highway when the need is to overtake large trucks and buses. The reason is on highways these vehicles cannot hear you as they are battling with sleep, fatigue ,there is too much of engine noise in their cabin, radio is switched on at times or they are chitchatting while driving and worst, talking on mobiles in one hand. You flash at them to make your presence felt you realize that they do not have side view mirrors at times hence they cannot see you or your flashing lights. The twin tone air horn is the best to grab their attention while overtaking on highways. Forty foot container truck are long and your horn needs to have their attention to make your presence felt by them.....
 
Hence, the horn would be installed via an extra switch and would only be used only on highways......
 
Thanks and regards,

Siddharth Talageri

If you really feel the need for additional horn, you can look at the range from Roots.
However, I would suggest you to take the normal diaphragm types and not opt the air horn (trumpet type) as these are illegal.

Are you planning to install these inside the bumper or visible on the outside?

Inside the engine bay.... I know that they are illegal but would use them where they are are to be used and not in city or citylimits.....

We have twin tone horns and they are only illegal if each tone sounds extra ie with a gap in between like a police car but if they both go at once they are allowed