F5 MFG Modular Stock System MSS for MP5 And Variants Flat Dark Earth 3in x 6in x10 in F5-MP5-MSS-FDE. The manufacturer says that F5 MFG Modular Stock System MSS for MP5 And Variants is compatible with Heckler & Koch MP5F5 MFG F5-MP5-MSS-FDE: Modular...