I didn't buy from Amazon and needed Friedland advice on technical issues. I have to say that (using e-mail), good simple to understand advice was quick.
However, my main gripe was the fact that every time I armed or disarmed the alarm, the outside unit emitted a loud beep - one for armed or two for disarmed. This would not very popular with the neighbours, so I asked which units had this 'feature' and their response was 'Most of our systems will beep when armed/disarmed but they usually have the facility to switch the beeps of (for example SA1/2/3 & SK1/2/3)'. Remember, this is the OUTSIDE unit - not the internal keypad, which is where most other suppliers have their reaction indications. This unot I got was one opf the cheapest, the WHA1, so I felt confident that the more expensive units would be better - clearly this is not the case. Mine has now gone back for a refund.