Q'Straint MM-320 M Series Occupant Securement Integrated Lap Belt. Attaches the the Rear M Series Wheelchair Tie-Downs Straps. Q’Straint provides customers with a wide assortment of occupant restraint options that allow our customers to select the best choice for the passenger and vehicle layout. A Lap and Shoulder Belt are vital in ensuring the safety of your passenger; securing the wheelchair alone will not guarantee the safety of your passenger.