Duracell SpecialtyAlkaline AAAA Battery 1,5V, pack of 2 (LR8D425) designed for use in digital pens, medical devices and headlamps: Amazon.co.uk: Electronics & Photo
AAAA alkaline batteries - Duracell Specialty
2) Duracell® AAAA Alkaline 1.50V Standard Battery Box | eBay