Quickboost products are manufactured in the Czech Republic and are intended to improve or add detail to currently available plastic model kits. In this case, the product is a replacement rudder for the late model JU-87D and G Stukas operated by the Luftwaffe late in World War II.
The product consists of a cast resin one-piece rudder. The idea is to trim off the kit’s existing rudder and replace it with the resin unit. Looking at both parts together, it is difficult to see any significant differences, although one advantage would be that it would be easier to position the rudder to the left or right, rather than cutting off the kit rudder (and probably screwing it up) to get the same effect. The details on both rudders are similar, although the resin unit has the cutouts for the rudder hinges molded into the resin, whereas, these are missing on the kit unit.