The Würth (M-Cube) adapter in the Brennenstuhl multi-battery 18V system is used for using the 18V batteries in one of the multi-battery LED construction lights. Attach the adapter, plug in the appropriate battery and you're ready to go – the adapter can be used at the Brennenstuhl interface in the spotlight. The Würth Adapter also convinces by the following features: Easy locking mechanism without screws Handy design Ability to use the 18V battery system of your choice