APF MARK 21
The APF MARK 21 is an arithmetic calculator with 8 digits precision and algebraic logic. It has 6 functions, 24 keys, and a VFD (vacuum fluorescent) display. The power source is Sealed battery pack.
Facts at a glance:
|Power Source||Sealed battery pack|
If you have an APF MARK 21 that is no longer working, you can consider replacing the calculator with a modern equivalent. We suggest the following current models as possible replacements: