This is the Clansman 14.4 Volt Rechargeable Nickel Cadmium Battery Pack, capacity 4Ah. The battery is used with some Clansman Man-Pack radios such as PRC-350.
The metal battery pack is supplied in used condition and may not last for long. However as they are metal construction with the top riveted on they can be taken apart for cell replacement.
See this excellent article on
Refurbishing a Clansman Battery on VMARS website.