Wera '05020100001 6004 Joker S Self-Setting Spanner, 10-13 (7/16"-1/2") by Amazon.co.uk

• The adjustable Joker 6004 covers all metric and imperial dimensions in the respective field of application

• Automatic and continuous grip of hexagon screws and bolts

• Lever mechanism when gripping avoids slipping and damage

• Fast and consistent screwdriving without removing the wrench thanks to mechanical ratchet function

• Return angle of only 30\xb0 through placement in the corner-width rectangular prisms in the mouth