Another great mouse from SumVision, this one is very affordable yet features an ergonomic design and- as expected nowadays- an optical sensor. Plus the all-important scroll wheel.We've no idea why they called it "Ruby". Maybe they liked the red colour of the sensor), but it's not particularly "Ruby"-ish otherwise, so we've no idea. Doesn't really matter because this is another mouse that beats many costing several times its price.Ruby ruby ruby ruby!Includes both USB and PS/2 (round emerald green mouse socket) connections, so will work with almost any laptop or desktop PC built in the last 15 years!