A mortar is a muzzle-loading indirect fire weapon that fires shells at low velocities, short ranges, and high-arcing ballistic trajectories. It typically has a barrel length less than 15 times its caliber. The weapon can be disassembled into approximately 15 lb components which allow it to be transported by soldiers. The fin on this weapon is designed to control and stabalize the ballistic while in flight. Gayston has manufactured fins for both the 61 mm and 81 mm rounds .
M29 Fin for the 81mm Mortar

81 mm Mortar
more information on the 81mm mortar