Verbatim Premium CR2450 lithium coin cells are 3-volt, single-use button batteries used in car remote keys and key fobs, bathroom and kitchen scales, fitness and heart-rate sensors, some watches, bicycle computers, smart-home sensors and medical devices. Lithium chemistry gives a flat voltage curve, a long shelf life and good performance in cold conditions compared with alkaline button cells. Each CR2450 cell measures 24.5 mm in diameter and 5 mm thick and weighs about 6.2 g; it is the same size as the DL2450/ECR2450 designations used by other brands, so check the old battery's marking before replacing. Verbatim packs these cells four to a child-resistant blister card. This listing is a bulk quantity described by the supplier as '(4 Pack) 20 Pack', which suits resellers, workshops, facilities managers and anyone who keeps a stock of replacement cells for many devices. As with all coin cells, keep them away from children: swallowed lithium button batteries can cause serious internal injury, and used cells should be recycled rather than binned.