This pack of 2 Duracell Electronics lithium CR2016 batteries are ideal for calculators, handheld games and toys. To help ensure the safety of your children, they have been designed with Baby Secure pack: Tamper-proof pack with double blister so that it is impossible for a child to open without scissors and a non-toxic bitter taste ring-shaped layer with Bitrex applied on the backside of the cell to discourage swallowing from babies and toddlers.