Using these Fischer Duopower 8 x 40 S wall plugs is easy. First, drill a hole in the wall that matches the size of the plug. Make sure to clean out any debris from the hole. Then, take the plug and insert it into the hole. The narrow edge of the plug will prevent it from going too deep. Next, insert the appropriate screw into the plug and start tightening it. You'll feel when the anchor is properly seated. When working with these plugs, always wear safety glasses to protect your eyes from any debris. Also, make sure to use the right - sized screw for the best hold. For maintenance, these plugs are pretty low - maintenance. Just keep them dry and away from excessive heat or moisture. If you notice any signs of damage, replace the plug to ensure a secure hold.