This set contains a resin jig that will allow you to center drill the spinner from BR32122 Bf-109G-6 Prop and Spinner and BR32123 Messerschmitt Bf-109G-10 Prop and Spinner. It also contains a blade alignment jig for the standard 109G-6 type prop blade as well as the wider paddle G-10 style blade. This set is cheap, easy to use and reusable! A must have for the dedicated Gustav and Kurfurst builder.