Industrially manufactured Czech hedgehogs were made of three pieces of metal angle (L 140/140/13 mm, length , weight ; later versions: length , weight joined by gusset plates, rivets and bolts, or welded together into a characteristic spatial three-armed cross with each bar at right angles to the other two. (This pattern forms the axes of an octahedron.) Two arms of the hedgehog were connected in the factory, while the third arm was connected on-site by M20 bolts. The arms were equipped with square "feet" to prevent sinking into the ground, as well as notches for attaching barbed wire.