Well I picked up a couple 507T's for a good price on ebay from a good dealer, recieved them today and noticed an odd difference.. see pics below.
First difference: The clear one is made in taiwan, the black in china.
Second difference: The clear one(taiwan) has a 3 amp fuse, the chinese model has a 1amp fuse.
Third difference: On the sides of the module, the chinese has 4 toggle switches, the taiwanese has 3. Only difference is the 2002 model has option for 10 second or 120 second delay before arming sensor after alarm is armed.
Fourth difference: The instructions are copyrighted different years.. The chinese black 4 switch is 2002, and the taiwanese clear 3 switch is 2000.
Similarities: They both have the same fuse holder and wire gauge.
Anyways, I was mostly curious as to which it would be more wise to use on my upcoming alarm install. I assume the 2002 model, I think I have sene an even newer model as well on ebay, are there any advantages to it over these two?