For manual operation. With inside square and inside hexagon insert. With clamping ball for bits. Surface: chrome-plated. Made in Germany. for inside hexagon profile 6.3 = 1⁄4″ – Inside square (Robertson) 6.3 = 1⁄4″. Total length (for class): 23.5 mm. Drive: Square, hollow 6.3 mm (1/4 inch). Output: Hexagon, hollow 6.3 (1/4 inch). Net weight: 0.02 kg.