This is a RG-42 Grenade paper model, the designer is Bob Navratil, this is a full size papercraft. The Soviet RG-42 was a fragmentation grenade originally introduced during World War II as an emergency measure, continuing in use with the USSR and its Warsaw Pact allies in the post-war period. It contained about 200 grams of explosive charge (TNT) in a cylindrical can. The grenade could be thrown about 35-40 meters and has an effective blast radius of around 10 meters. The total weight of the grenade with the fuse was about 500 grams. It used the 3.2 to 4 second UZRGM fuse, also used in the RGD-5, RG-41, and F1 grenades.
You can download this papercraft from here: Soviet RG-42 Grenade Full Size Paper Model Free Download