Wera | 7880 Joker Self Setting Spanner Insert - Various SizeSquare head insert tool 14x18 mm. For torque wrenches from the Click Torque X series with 14x18 mm mounting. Automatically and continuously gripping hexagonal screws and bolts. Lever mechanism upon gripping prevents slipping and damage. With mechanical ratchet functionality for fast and consistent screwdriving without removing the spanner. Return angle of only 30 when using the corner width rectangular prisms in the jaw.