DS had changed spark plugs in my car and left the mess for me to clean up. I was recycling the plugs when my DS said NO leave 1 in the car. He has worked as a car repo man and says you can use the round tip to shatter a window if you have to I have electric windows so I put it under the drivers seat. I do construction repairs and keep a claw hammer in the trunk. Would not hesitate to use either if I saw a child or animal locked in a vehicle.