of the device 100 moreover the right side 122 is adjustably connected to the lower portion of the front surface 105 the right side extension 122 is adjustably connected to the front surface 105 through interaction of bolt and slot assemblies 126 127 in this embodiment the bolt portion is part of the right sidewall 104 while the slots are part of the right side extension 122 the right side extension 122 includes a contoured bottom surface 130 that defines a belt contacting surface being preferably but not necessarily approximately the same width as the right shoulder strap 160 up down adjustability of the right side extension 122 provides up down adjustability in the distance between the bottom surface 130 of the right side extension 122 and the bottom surface 108 the right sidewall 104 this affects forward pivoting of the device 100 the height of the surface 128 relative to the surface 106 and the height of the surface 130 relative to the surface 108 ratio thereof limits the amount of load grip or holding of the device 100 on the shoulder straps 150 160 before the device 100 pivots cantilevers forward and moves with the occupant during deceleration the device 100 moves while maintaining its pivot or cantilever angle typically and preferably but not necessarily the two.