If your alarm takes one small battery, there is a very good chance it is a 12v circuit. These batteries fit the (vx range, vc range, theseus camo range ) These are 12volt and do fit many other alarms, please check the dimensions below...Special offer on 5 or more...(just 50p each)

A23 type, 12volt, 28mm (L) x 10mm (W) alkaline plus

Please note, the price breaks above are per unit. ie 3 batteries x 0.75ea = £2.25