COMPATIBLE: Works with eXtreme Dog Fence Hyper (stubborn dog) collar (light blue strap with blue rectangular receiver) COMPATIBLE: Works with Perimeter Technologies stubborn dog collar (black strap with black rectangular receiver) LIFE: After the first battery is depleted, subsequent batteries have an average life of about 4 months SHELF LIFE: Your batteries will hold for 3 years when stored in a cool dry place POLARITY: The battery will go into the collar negative side in first. Positive side closest to outside of the receiver