Using your Deejo 27g Pocket Knife is a breeze. To open it, simply use your thumb to release the liner lock and unfold the blade. When closing, make sure your fingers are clear of the blade path and gently push the blade back until the liner lock engages. For safety, always keep the blade closed when not in use. As for maintenance, after each use, wipe the blade with a dry cloth to remove any moisture or debris. You can also use a little knife oil on the blade and moving parts to keep it working smoothly. Avoid using the knife for tasks it's not designed for, like prying, to prevent damage to the blade and handle. With proper care, your knife will last for a long time.