Product information and features: COLOUR: YELLOW 22 W x 23 H x 43.5 L To prevent very heavy-WEIGHT vehicles from rolling application PROCESS: Place behind rear wheels of TRUCKS (as two are required). It is important to choose the right size stop block for the type and size of vehicle it will be used for. Please note that STOP BLOCKS (Wheel Chocks) are not intended to be driven over and improper use may result in failure