disclosed is a system for quickly and easily installing end - of - line termination devices at the end of alarm system signal circuits . the termination devices in this invention are both variable and integral to the housing of the alarm system devices . each alarm system device is constructed with a receptacle at the point of protection , in which may be placed a cartridge , jumper , or similar device on - site to terminate the communication signal . the various embodiments of the invention include a set of devices at discrete values or a variable device to complete each protection loop .