Leuku has a long, wide, and strong blade that is more suited for light chopping and shelter making than fine carving, so it is not well suited to whittling. It is used instead of an axe for firewood, wood clearing, bone-breaking, and other works. Typical leuku has a blade length ranging from 200 to 450 mm. Largest of the leukus actually can be considered as machetes or short swords. The handle of leuku is invariably made from birch. The tang runs through the handle. The handle has no crossguard. Traditional material for the sheath is reindeer leather.
Sami normally use two knives; the smaller one can be called a puukko since it is so close to the Finnish puukko. Saami call this knife unna-niibas and the bigger, leuku, stuorra niibas.
Leuku is also a well-known Finnish on-line photo agency