Arduino as alarm controlling an external siren

Hello all, I am setting up domotic console using an arduino mega with ethernet shield, solar shield + lipo battery and a gsm shield. Am creting bricks of sensors consolidating signals to attinys who then transmit data to master using rs485. Am also embedding alarm functions into the console, and would like some guidance on that: Am testing things so am not able to say yet if everything works properly (using divide et impera/divide and conquer things do work, now want to put it together)... however an alarm without a siren is not an alarm and would like to finalise a design witrh that piece as well before.

I went out on the market and am interested in the 95 model described here, specs are here (I apologise ... did only find it in Italian). My plan is to control it through a 12V relais directly connected to a mega pin.

My question is: is it to you enough connecting a 12V relais to arduino to pilot this object? Does anybody have any eperience in connecting similar products? What would you recommend considering ... apart a separate power circuitry as arduino will never release all the amperes required to activate that?

Any suggestion is welcome... and thanks in advance, also for your patience because am sure info is not enough. Cheers, Marco