I BOUGHT THE MACE PRE-PACKAGED SECURITY KIT. I HAD TWO LARGE ROOMS TO COVER EACH IS ABOUT 30 FEET WIDE WITH ONE BEING ABOUT 40 FEET LONG AND THE OTHER, 20 FEET LONG. THERE WAS NO NEED FOR THE DOOR SWITCH SO I'LL USE IT ELSEWHERE. THE EXTRA "PIR" COVERS ONE ROOM WHILE THE SECOND "PIR" DOES THE SECOND. NOTHING GETS BY AND, IT WAS AN EASY SET-UP. LESS THAN AN HOUR AND THAT INCLUDES TIME TRYING TO TRICK IT. THE KEYFOB, I LET MY KIDS USE IT WHEN THEY VISIT. I MADE ONE CALL TO CLEARIFY THE WAY SOMETHING WAS WRITTEN; EXCELLENT CUSTOMER SERVICE/SUPPORT. I ALSO BOUGHT THE ALARM HORN