Using your Klein D507-8 adjustable wrench is easy. First, open the jaw to fit the fastener you want to turn. Just turn the knurl on the side to adjust the size. Then, place the wrench on the fastener and start turning. It's great for tight spaces because of its extra capacity. When using it, make sure the wrench is firmly on the fastener to avoid slipping. As for maintenance, keep it clean after each use. Wipe off any dirt or debris. Since it's chrome-plated, it resists rust, but it's still a good idea to store it in a dry place. If you notice any issues with the operation, like the knurl not turning smoothly, you can lightly lubricate it with some oil. This will help keep it working well for a long time.