Can be used on SAE or metric fasteners|Low profile design helps gain access to fasteners in tight spaces|Proto® Bolt Extractor Sockets can be used in combination with other drive tools (such as extensions, universal joints or ratchets with short arc swings) to help reach fasteners in difficult locations|Proto® Bolt Extractor Sockets make it easy to remove rusted, rounded or damaged nuts and bolts|Sets provided in mar-resistant tool holders.