That is an attachment lens designed to give a fisheye effect. The Bower VLB3852B 0.42x Super Fisheye Lens, is very similar to the one in your previous query.
Here are the key details for this specific lens:
Type: 0.42x Super Wide Angle/Fisheye Conversion Lens. This is a front-element attachment that reduces the focal length of your existing lens, widening the field of view and creating the distinct fisheye distortion.
Thread Size: It features a 58mm rear thread, meaning it is designed to screw directly onto the 58mm filter thread of your camera's main lens (such as a standard kit lens).
Color/Finish: Black ("B" in the model name).
Macro Functionality: Like other lenses in this series, it typically includes a detachable macro lens for extreme close-up photography.
Optics: It usually has multi-coated (MC) glass to minimize reflections and glare.
It is a common accessory for photographers looking to experiment with the ultra-wide-angle fisheye look without purchasing a dedicated primary lens.
