The " (52 Toku-1)" at the end of the product name is the item's serial number. This is a type of center-focus lens, with a transparent flat surface in the center and a frosted spherical surface around the periphery. Images taken with this lens have a sharp central area and a gradually blurring periphery. The lens barrel is also telescopic, allowing for various photographic expressions that emphasize the subject in the center, hence its other name, "portrait lens." This product's filter thread is 52mm on the camera lens side and 58mm on the front side. The product has quite noticeable scratches, but most are on the periphery, so I don't think they will significantly affect the image quality. I have included sample images at the end of the product images, so if you are concerned about the image quality, please refrain from purchasing.