Test fixtures are devices which hold units to be tested, such as electronic or electrical assemblies. They are available with various drive systems to generate a parallel working stroke to contact units under test. Test fixtures form the interface between the UUT / DUT and the test system. Test fixtures are available as interchangeable kits and stand-alone test fixtures. Interchangeable kit test fixtures offer the advantage of testing different exchangeable kits with only one basic unit. All test fixture and exchangeable kits are modular and have a similar functional principle to generate the parallel contact stroke to contacting the electronic assembly. The test fixtures consist of the fixture housing and a drive unit, the exchangeable kits consist of a pressure frame unit and a probe plate unit.