I hope I can get help with my question. My PSU is 220 watts on my acer model. It's length is 73/4 inches, width 2 inches and height 31/2 inches. On Amazon there is a psu of 500 watts I'd like to buy. I believe it looks identical to mine in shape. The brand is Shuttle. My computer is SFF or small form factor. Would this new Shuttle PSU 500 watts fit to my Acer model? Any help would be greatly appreciated!