8 screws М5х7 from B-31L is needed to fix the B-31L on the DL-1 and B-10L in case you will not use the side plate. If you will, then you should use 6 screws M5x7 and two screws M5x9 (longer), which are included in the DL-1 kit. The plate is installed with longer screws. They cannot be used in other attachment points. 8 screws М5х7 from the B-10L forend kit are required if you plan to install the B-33 receiver cover, the bracket over the B-22 rear sight block, and also use the B-10L outside the "Sport" kit together with brackets above the B-19 gas outlet pipe or B-19N. Please note that brackets B-19, B-19N, B-22 and B-33 are equipped with longer M5x9 screws, which cannot be used with the "Sport" set.