Compatibility: Designed as a replacement shifter button for DCD777 and DCD778 cordless drills. Function and benefits: Enables easy switching between speed settings, allowing you to select the appropriate speed for each task to improve efficiency and achieve precise results. Material and durability: Made of plastic, this shifter button is built to last. It resists wear and tear and offers reliable performance in challenging work environments. Easy replacement: A practical option to worn or damaged buttons. Remove the old button and install this one to restore your cordless drill's functionality quickly and effortlessly. Use scenarios: Drilling wood or metal: switch between low speed for precision pilot holes and higher speed for faster drilling to suit the material. Driving screws: use the correct speed to control torque and prevent stripping or camout. Overhead or delicate work: select slower, steadier speeds to improve control and reduce heat buildup.