The Raynox HD2205 is a 2.2x Telephoto Conversion Lens that extends your camcorder's effective focal length and makes distant objects appear larger and closer without having to move closer.  This lens' supreme optical magnification, with a whopping 200-line-pairs-per-millimeter peak resolution, doesn't spoil image quality as using a digital zooming system would do.  It has 37mm native rear threads, but comes with adapters so that you can use the HD2205 on cameras which accept 27mm, 30mm, 30.5mm, 34mm, 37mm, or 43mm filters.

Giving further example of its professional nature, the HD2205 also comes with a dedicated lens shade.  This shade provides 59mm of length to the end of the lens barrel to avoid the introduction of stray light into the optical system, and is an invaluable accessory whenever you're shooting in a glare-filled scene such as around water, sand, or snow.  The shade attaches to the lens front's 55mm standard filter threading, which also means you could place a 55mm circular polarizer or neutral density filter in between the HD2205 and its hood to further increase effective contrast in bright light.