"Pineapple" Grenade Mark IIA1
This frragmentation grenade of US forces during WWII, with an M10 Fuse. Inital versions were painted a high visibilty yellow color, but these proved to be a handicap for jungle fighting. Later they were switched to Olive Drab color.

It contained an explosive charge in a body designed to fragment with the action of the bursting charge . This type of Hand Grenade originated in WWI (August 1918) and contained either 1.85 oz. of TNT, 1.85 oz. of Amatol 50/50, or a filler of Trojan powder . Various models of ’Mk II Defensive Hand Grenades’ were used, with different types of fuzes and fillers, with a delay time of anywhere from 4 - 5 seconds.