WERA WER-020101 - 6004 Joker L Self-Setting Wrench 16 - 19mm (5/8 - 3/4")Features Automatic and continuous grip of hex screws and bolts Automatically adjusts to different size bolt heads Lever mechanism when gripping avoids slipping and damage The single arm design along with the ratchet function make this a great tool for confined spaces Fast and consistent driving without removing the wrench due to its mechanical ratchet function Back pivoting angle of only 30 degrees with placement in the corner width rectangular prisms