I purchased new mantra for my daughter with anticipating to use the embedded blast sensor. little did we know that we needed a special key from blast too insert and remove the sensor.. the serial number on blast needs to have second number on top row to be 5 or higher to be compatible (we have that) but we don't have the key. didn't come with sensor purchased in the beginning of the pandemic before mantra was released.. needless to say blast sells them for 10 bucks a piece ... I emailed them waiting to hear back maybe receive one gratis but already ordered two to be shipped (27$) figured one will be inevitably lost or misplaced by myself or daughter lol.. bat is awesome thus far using the blast in real time live game is still being looked into ..just wanted to let people know who own already own the blast to know about key, I think now all blasts are being shipped with key.. I purchased bat from CORE a wonderful experience and highly recommend his services..best of luck in seasons for all the daughters who are lucky enough to play in this new world we are living in...stay healthy all