Abstract: An improved device for immobilizing or impounding any vehicle includes a pair of jaws that can be brought together on either side of a wheel to capture that wheel. A chock of width equal to the wheel rests against the ground and prevents movement of the captured wheel. The device is preferably made of hardened steel and is assembled in such a way as to make non-destructive disassembly impossible. The design and construction of the device make it impossible to twist or otherwise misalign the jaws or the chock of the device, except by use of extreme and excessive force.