1/4" deep length sockets hexagonal.Metric sizes, thin-walled.Sockets are applicable to nuts and bolts used in the aerospace industry.Not suitable for machine operation.High-performance alloy steel.Knurled area for better grip.Applicable to nuts and bolts used in the aerospace industry.Dynamic-Drive™ Profile to protect the nuts, screws and tools from unnecessary wear and damage.Standards: ISO 2725-1/1174-1, DIN 3120