Calamander
Intercoms, bike to bike communicators and walkie-talkies for use on motorcycles etc. we ship worldwide
http://www.calamander.co.uk/intercoms/intercoms.htm
Dile
Dile
http://www.dile.nl/index.html?microfoons_helmset.htm
Velltec
Velltec
http://www.velltec.com/helmen.htm