5 Big is beautiful! Batteries NOT required!JimFixIT | 11/03/2011 | See all JimFixIT's reviews (9)Top 100 Mobile Reviewer Having initially bought a compact wireless mouse for my laptop, I quickly realised my error because those micro-sized mice are best suited for the small hands of children and not for prolonged use of an adult. I soon found my fingers and hand sore from even moderate amounts of surfing. Also I was frustrated at having to constantly replace batteries.This proper-sized mouse is exactly what I should of bought in the first place. My hand fits it like a glove and I never need worry about replacing batteries again.All in all, pain-free pointing perfection delived to your door for a fiver.Well done Logitech, Well done Play!