m26 grenade
A fragmentation hand grenade developed by the United States military. It entered service around 1952 and was first used in combat during the Korean War.
Its distinct lemon shape led it to being nicknamed the "lemon grenade" (compare the Soviet F-1 grenade with similar nickname).
The grenade was developed as a result of studies on the Mk2 grenade. The M26 series was created after World War II to meet criticisms of the Mk 2. It was replaced by the M33 series grenade (M33/M67 at the end of the Vietnam War.