To use this spanner, simply place it on the screw. The self - setting feature will adjust automatically to fit the screw size. For driving screws, use the mechanical ratchet function for quick and consistent results. When working, make sure the spanner is fully engaged with the screw to avoid slippage. As for maintenance, keep it clean after use. You can wipe it with a dry cloth. Avoid using it in extremely wet or dirty environments as this may affect its performance. If it gets stuck or doesn't work properly, don't force it. Instead, check if there's any debris inside and clean it carefully.