i have two fobs with mine, no siren. I've considered the siren, does it go tweet when you set the system? I somewhat prefer a "no tweet" on activation

 

It does chirp a couple of times when arming and disarming.

The manual says there is a procedure to disable the chirp, but I couldn't get it to work.

 

My 08 FatBob came with 2 Fobs from the factory. Iadded the siren. It's fun to play with.It also brings attention toyour bike ifmoved. Last year at a bike rally, I gotboxed in by2 bikes parked sideways, against the grainso to speak. I pushed them both out of my way with lights flashing like crazy but nobody paid any attention to the silent alarms.
My 03 Vrod came with 2 Fobs also from the factory. I never used them or the security system though. The battery always died if I leftit armedmore than 1-1/2 weeks.

 

Two fobs and a siren - chirps are a bugger to turn on and off but can be done if you are really fast on the button pushes as described in the manual. I like them as they remind me its armed etc. My siren isolates easily enough too - again all in the manual.