Item #70807 HR/AR2. Tandem Truck Suspension. (1 Pair) This suspension system also comes in a split version with rubber airbags.
1/25 scale is 57mm in length on the bottom beams (52mm center to center on the axles).
1/24 scale is 59 mm in length on the bottom beams (54mm center to center on the axles).
1/16 scale is 89mm in length on the bottom beams (82 mm center to center on the axles).