As above groups is way it's done on dimension, I used to use a code and code reversed
Although jw there is a part set on the dimension no? Or I assume he wants and extra part set
You would still expect to pay decent money , rather than using £20 chimes although you might think they do the trick but that would depend on how seriously your taking an intruder alert
Commercial wired systems or via WiFi cost more as they tend to work better and more often
I assume the school has a fire alarm commercial not battery operated smoke detectors for the home? No sarcasm intended
Not really Samsung makes some good items , IP stuff is okish not very friendly when mixing gear and hikvision also has it top end hear that you wouldn't buy
But it is junk what you bought , it was better you bough new , or atleast returned on eBay within time , within 6months of PayPal
Be serious lol
Some get confused between having a fire alarm installed and a buildings fire consultation report if that's what it's called , I tell them , it's not the fire engineer who would do this as far as I know