I bought Optical mouse from DELL. The mouse is silver and black in colour and DELL is written on top with silver colour. There is a wheel in the centre and this wheel is very helpful in moving the page up and down. The Optical mouse from DELL is connected to the computer desk top via a connecting wire. There is no rolling ball in the bottom of the optical mouse but a red light lit and does the same job. I find Dell Optical Mouse better quality than traditional mouse with the ball. My experience is that the optical mouse last longer and more comfortable to move.
I am using computer since 2000 and in these seven years I tried different varieties of mouse and now I can tell others the optical mouse from Dell is one of the best quality of mouse I ever tried. Its been three years since I bought the Dell optical mouse and it is still as good as new. Previously I had to replace mouse after every 6 to 8 months. I am really thankful to Dell for producing good quality products. I paid few bugs extra and was not happy at all but now that extra bugs are paid off . Dell saved me money (in the long run) and also hassle.