0.45x wide angle lens for Nikon 50mm 1.8 Series E lens?

I have a Nikon d3100 and a 50mm 1.8 series E lens. I'm planning to get a 0.45x wide angle lens. I'm wondering if there will be bad vignetting? I also have a 18-55mm kit lens too. Should I get this wide angle lens?

Added (1). The thing is that a 50mm 1.8 has much better image quality than the 18-55mm. Adding the wide lens to the 50mm maybe a good choice?

Your 18-55mm lens is wider than your 50mm with a 0.45x lens on it. Multiply 50 by 0.45 and you will see that it will turn your 50mm into a 22.5mm lens.

Nope. Those cheap screw on filter lenses are garbage which will seriously degrade your image. Your 18-55mm would be better.

Vignetting woul be the least of your problems - those wide angle filters are rubbish - with terrible image quality.

Yes you are 100% correct that a 50mm 1.8 has much better image quality than the 18-55mm.

But as soon as you srew in that 0.45 adapter you may as well be taking the photo through the bottom of a bottle. It will introduce barrel distortion and chromatic aberration like you never saw before!

Don't waste your money!