The standard Japanese grenades were the Type 91 and Type 97 grenades. The Type 91 had a 7.5-second fuse and adapters to allow it to be used either as a rifle grenade or as a projectile for the Type 89 "knee mortar." Both were filled with two ounces (57 grams) of TNT. The Type 97 had a 4.5 second fuse (though it is 3 seconds only ingame) and was used only as a hand grenade. Both broke into very small fragments that were less lethal and had a much smaller kill radius than the corresponding Allied grenades. The fuse was rather unusual, being lit by banging the grenade on any solid surface to drive a firing pin into an igniter. The fuse was also unreliable if stored for any length of time, tending to go off too quickly.
The Japanese apparently planned to replace these rather dangerous and ineffective grenades with a model that used a friction igniter. However, few of these grenades were ever manufactured and their effectiveness is unknown.
