I have a 'Foxpro' remote control caller, I bought it in America, but you can get it here.
YES it's the best thing out there! the remote works up to 700 yards so after all my previous experience with mouth blown calls, and a heap of dead foxes, it's still beats the competion into a pulp.
The main advantage over 'personal' calls is that 'YOU' are not the scource of the squeeking, the scource is were you decide it will be, so you can hide up in a convenient spot sighting the Foxpro in an equally convenient location, then press button 'a' to activate the call and wait for the action to start.
T