This is the two position rear carrier with a spring loaded mounting plate. Mounting plate can either be secured in the default up position, or can be fixed in the down position by use of the accessory clip.
Accessory Clip available at this link: Rear Carrier Clip
*For reasons that cannot be explained, this rack is virtually identical to 1B002106. The only difference being that this rack has a rear plate that is 8.325 inches by 13 inches where 1B002106 has a rear plate that is 8.5 by 13 inches. Why Vespa built two nearly identical racks... we'll never know.