Entering service in 1929, the Type 89 launcher was a dual purpose weapon, capable of firing both the standard Type 91 fragmentation grenade for anti-personnel work, and also the Type 89 round, which was closer in potency to a true mortar round. The "Knee Mortar" designation came about due to GI's observing that the curvature of the base plate (meant for use with a tree trunk) would make a good fit for a human leg; an observation that led to a number of injuries from the heavy recoil of the weapon. Overall length is 23 3/4", with the barrel marked with the serial number over a set of arsenal proofs, the full serial number on the barrel mounting ring, main spring tube, and base, "399" on multiple small parts, the range adjustment wheel mounted to the right of the main tube, spring loaded rubberized canvas dust cover and curved base plate. NOTE: This weapon is defined by the National Firearms Act as a Destructive Device. This is a fully transferable NFA Class III Firearm currently on a Form 4. You are required to check your state and/or local laws as to whether or not you may own this. This weapon can be transferred to a Class III dealer at no charge. Buyer pays all other transfer fees and stamps.

Fine with 75% of the original blue finish, showing areas of brown patina, scattered spotting and mild handling marks. The canvas dust cover remains supple with some material loss on the high points.