The product listed here is Aftermarket Replacement flip key shell suitable for Compass Trailhawk 2 button flip keys. It is an empty key shell case there is no electronic circuit / battery / transponder chip inside it. INSTRUCTION FOR INSTALLING OR REPLACING KEY CASE: 1) Open your keys' remote body with a screw driver. 2) Remove the front remote case/panel from the case. 3) Remove the transponder chip from the case. Be careful that you do not damage the immobilizer chip. 4) Remove the chip from the original key shell & Install the chip (of your existing key) and remote body onto the new remote case the same way. 5) Get the key blade cut with the help of your nearest auto locksmith. In case you are not able to understand the installing/ replacing procedure please visit your nearest locksmith and get it done.