Oblong master links are typically used at the end of rigging assemblies, and most often, they are used on one end only. They are called master links because in a traditional rigging assembly, the master link is on top, connecting directly to the crane hook while the rest of the sling hangs below it. These master links feature enlarged interior dimensions--they are both wider and taller than regular master links. This is important because they will fit over a wider range of crane hooks in the field. Ideal for use with chain slings. Each link is proof-tested and certified with a 5:1 safety factor.