SENA communication system advice please !!

[JAS]

Hi Guys

I have a 20S dual set for me and my son and need to buy one for my wife who only rides pillion and not that often, but I need
to buy her a comms system too

Any guys with experience of SENA :  What should I buy ?

If I add a Sena 5 or Sena  10 can she talk to me and my son or will I have to buy another 20s ?

THX

 

[Chrisl]

 

[Platbrak]

 

[scubafriqe]