CR1220 coin cells are used extensively in miniature electronics such as watches, remote controls or even cameras. These batteries have a long storage life and a wide operating temperature range.
These particular coin cells have a diameter of 12mm and a height of 2.0mm, which can be identified from splitting up the first and last two numbers of the part code. This technique can be applied to any coin cell to give you the dimensions of the cell, which can help you to identify the right battery.
CR1220 coin cells may also be known as the part codes DL1220 or SB-T13, but they are all references to the exact same product.