1/4" 37mm Zyklop Screwdriver Bit Adaptor - 

Wera 8784 A1 Zyklop bit adaptor, 1/4" drive with Rapidaptor technology. Rapidaptor technology has been developed by Wera for rapid bit change without any extra tools and also only requires one handed use. Rapid-in allows the bit to be inserted without moving the sleeve, thanks to a self-lock mechanism the bit automatically locks in securely. Rapid-out allows for the bit to be changed by simply pushing the sleeve forward, this works via a spring mechanism lifting the bit off the magnet. Rapid-spin, a free-turning sleeve that allows screw steadying at the start of the screwdriving process. This makes it easier to apply the tool to the screw and also prevents any slipping from occurring. The Rapidaptor quick-release chucks hold both ¼" bits as per DIN ISO 1173-C 6.3 (Wera series 1) and E 6.3 (Wera series 4).