come on, grade does not matter with these alarms. the one i took out the other day, has all the electronics in the outside box, next to the four batteries that power it. at the end of the day no burgular walks around with a ladder in their hand, that would be a dead give away.

Yep they are Grade 1............

If a customer gives a budget then you do your best ..........If cost driven then Yale....If brand/ quality then I use the powermax.....

Main difference between two is one operate on 433Mhz and the other 868Mhz....features are pretty much the same...Oh and one other thing about

I took a yale out a few months ago and the bell box came of in my hands from the wall. No sound! Chucked box in van and went inside. UNPLUGGED the panel and still no sound and no warning. Took PIR's of wall and the Bellbox started going of in the van......had to laugh.

This was fitted by another famous conservatory company in the area i work in.