The Honeywell LYNXRCHKIT-SHA is a super high capacity battery backup for the Honeywell LYNX Series wireless alarm control panels. The LYNXRCHKIT-SHA is recommended for anyone that has an AlarmNet alarm monitoring communicator installed inside their LYNX control panel and wants (24) hours of battery backup. The Honeywell LYNXRCHKIT-SHA super high capacity battery is much bigger than the LYNXRCHKIT-SC standard capacity battery that is included with all LYNX Series wireless alarm control panels. Therefore, when installing inside a L3000 LYNX Plus wireless alarm control panel, you will need to use the alternate battery retainer clip for the LYNXRCHKIT-SHA to fit properly in the battery compartment. When installing the LYNXRCHKIT-SHA inside a L5000 or L5100 LYNX Touch wireless alarm control panel, you will need to use the notch to the left side of the battery compartment to hold the battery retainer clip in place. The LYNXRCHKIT-SHA also uses a larger sized battery connector so you will need to plug it into the larger plug on the LYNX Series circuit board. The Honeywell super high capacity battery backup is compatible with the older LYNXR-I and LYNXR-2 wireless alarm control panels but is not compatible with the original LYNXR-EN. The LYNXRCHKIT-SHA is of course also compatible with the newer L3000 LYNX Plus, L5000 LYNX Touch and L5100 LYNX Touch wireless alarm control panels. The LYNXRCHKIT-SHA is the highest capacity battery backup available for the LYNX Series control panels and is actually made up of (6) 3700mAh, size 4/3 A, nickel-metal hydride batteries that are connected in series.