Rotogrip can be summoned to action at a moment's notice and deployed, in-motion, from the comfort of the driver's seat. When a sudden snowfall or sub-zero temperatures makes driving conditions dangerous, the truck driver simply presses a button mounted on the cab's console. An electro-pneumatic piston lowers the Rotogrip's supporting arm, and a flail-like, radial array of rotating 30-cm lengths of 5-mm flat-link chain is drawn below the vehicle's drive wheels, providing instant traction and safety. When conditions improve the Rotogrip is withdrawn by another press of the button. There are three models available.