Type 89 Grenade Discharger

The Type 89 Grenade Discharger (Inaccurately known as a knee mortar by Allied forces) is a Japanese grenade launcher or light mortar that was widely used in the Pacific during the Second World War.

Type 89 Grenade Discharger in Days of Infamy
Les Dillon encountered the Knee Mortar when the US Marines returned to Hawaii in 1943. He hated how effective they were with just one soldier operating them.