This 100% inert practice grenade measures approximately 4.5" x 2.5" and weighs 1 pound 5.6 ounces. I believe this was manufactured in 1954 because it is marked "54" on one side. Grenade is hollow and has two holes one at the base and one on the neck. These were used for less dangerous training of military troopsto get them better at grenade throwing and aim placement.