1. Double-decked protecting rubber: two-layer thickness is high quality rubber; the total thickness is 5mm, better to prevent the damage of tires.

2.Double security :this product operates with the heterogeneous rocking handle ,and there is no same kind rocking handle now, especially installs the door lock in the jack place of rocking handle, uses the burglar-proof door and safe cabinet door lock techniques.

3. Double thorn needle: 5cm steel needle can be punctured the tire of locked trucks to prevent the trucks moving forcefully.