Duracell Specialty Alkaline MN21 Battery 12V, pack of 2 (A23 / 23A / V23GA / LRV08 / 8LR932) designed for use in remote controls, wireless doorbells and security systems : Amazon.co.uk: Electronics & Photo
Duracell Security 21/23 Alkaline 12V Battery - MN21 - Alkaline - 12 V DC - 1 Each - Walmart.com