The strands can interlock with either twill or plain weave. First-time DUI convictions result in one year of a mandatory ignition interlock device. In many jurisdictions a judge may also order the installation of an ignition interlock device. Class-3B lasers must be equipped with a key switch and a safety interlock. Stretchy wraps are generally made of knits such as jersey or interlock. The two pivoting blades interlock each other. The force-transfer mechanism is based on friction mechanical interlock guaranteed by expansion forces. The trigger had a mechanical interlock to prevent firing unless the bolt was fully locked. The vertebrae interlock on their sides and lower surfaces. A tripping interlock can be activated for an emergency situation. Their edges interlock by one scrolling upwards and one scrolling inwards. They act transferring the forces via mechanical interlock. The interlock serves to prevent unintended movement of the car. The shifter was joystick-shaped and had a thumb trigger interlock and "on-demand" four-wheel drive button. A starter interlock was added to models with manual transmissions.