Do not confuse this Kodak K 4.5 volt battery for 110 type cameras with the Timex K button cell.
This size of battery is obsolete. It has not been made since 2000 or so and stocks are nil. See the pictures for the shape and style.
There is some good news though, if you take a look at D. Scott Youngs page, The K Factour, he takes you through how to repack the battery using commonly available LR44 button cells (American 110 camera site). NOTE: the original site "died", Brian, MW0GKX, has managed to recover the text and has posted it on his site, the link has been updated to that new location.
538, 7K31, 7R31, KK, Kodak K, Kodak KK, RPX31, Size K,
not to scale.
Height × Width × Length.
|Chemical Composition.||Nominal Voltage.|
|See Above.||K.||11.4 mm × 17 mm × 40.6 mm.|