No clamps either end typically. In comparison to other hoses its IMHO often found to have a smoother exterior surface compared to others in the system since it serves a different purpose though older used hoses can develop more of a texture due to heat, exposure and age
Like hoses used for air cleaner to breather or in smaller version PCV applications the hose would normally had identification ribs to identify the maker/provider of the hose
Mid year example. Forgive the age and patina (rust and removed original finishes)