Autobody repairers realign both the structure and the panelling of both light and heavy good vehicles after they have been involved in collisions. This can often be a complex process as each collision will present different degrees and directions of damage. The repaired vehicle must conform to the stringent specifications laid down by the vehicle manufacturer and meet both their tolerances and their safety specifications. An autobody repairer needs to be familiar with mechanical components and their function as well as the specific and often complex safety restraint systems (SRS) fitted to modern vehicles. The autobody repairer returns the vehicle to a condition where it ready for refinishing by a car painter.