When doing a dash roll-up, place the Ram Jammers against the B-posts on each side of the vehicle. Then, instead of only getting one push with hydraulic rams, Ram Jammers give you a secure base to make a second and then a third push for the Maximum Dash Roll-Up. This will give you a large amount of room in the front of the patient making it easier to apply spinal immobilization devices. They also absorb the force of the rams to prevent fractures at the B-post. Sold in set of 2.