Faun

Hi! I'll try and keep this short and sweet. I used to work for a security company installing intruder alarms for 2.5 years. I recently took a year out of the industry, I start my new job next week so I'm looking to brush up on the things I've forgotten. I'd like to know the specific details of the difference between a grade 2 and grade 3 alarm. As I understand it, grade 3 must have anti-masking and also a metal cpu/psu. Any further detail into the differences would be greatly appreciated! Also I've installed many grade 2 wireless intruder alarms in the past but I've always wondered, can you get wireless indruder alarms that are grade 3? Please give as much detail as possible! Thank you for all help given!