Using this viewfinder is easy. Just connect it to your camera with the included connection cable. Since the power button key cap is missing, be a bit careful when pressing the power button to avoid any accidental damage. There's no need to worry about the functionality as it works just fine without the key cap. For maintenance, keep it in a dry and clean place when not in use. Wipe it gently with a soft cloth if it gets dirty. This viewfinder can be a great addition to your camera setup, offering a clear color view for your shooting needs.