Large amounts of materials are received by such large vehicles, transported by forklifts, etc., and stored in the logistics warehouse. The mass of materials is also considerable, and the combined weight of trucks and forklifts is enormous. The lower rail of a regular folding door is exposed above the floor surface to receive heavy weight, which increases the A/S incidence due to the weight and impact of the vehicle.​

The lower rail is designed to fit the car center unlike the standard folding door, with less damage and wear, and the upper runner is designed to drive smoothly.​

It minimizes protruding areas on the floor, allows smooth driving without interruption when the vehicle passes, and minimizes the occurrence of A/S by distributing weight.