Granada Batteries offer a small range of AAAA batteries, yes quadruple A size batteries; even thinner than the AAA. This special size is a little more difficult to find on the high street, but AAAA batteries are being used more and more as equipment manufacturers look to reduce the size of their electronic equipment. They are also known as MX2500, 25A and LR8D425.
As usual, you can buy these in small or large quantities. Simply click on each product to see the wholesale discount prices.