Alarm system help

Good morning
I am attempting to help a couple ladies that have an alarm system that Myron Mortimer installed, just before he died. The system is functioning, but he had added a second wireless siren, that is not working. There are no manuals available, I have spent several hours looking online, but am unable to locate one.
The model number of the wireless siren, KR-J008, and is white, about 8 inches tall, 4 inches wide and has a red round bezel over the LEDS.
If you have one of these sirens, and the manual available, it should would be appreciated if I could make some copies.
Thanks

You might consider contacting Danny Garcia at S.O.S.E. He is familiar with the type of alarms that Myron installed. In fact, we had him replace one that Myron put in with the S.O.S.E system. And he took our "Myron" system to use for parts for people who do not want the S.O.S.E. system. Danny can best be reached on his cell phone 331-041-4247. The office number is 765-4921. All English speaking staff

Stillwaters
Thanks, that is a big help.
I had been directed to S.O.S.E, via word of mouth but was hesitant to contact a competing enterpirise.
thanks