Old ScubaPro Canister Light Question

[Shinythings]

I found an old scuba pro can light for sale locally at a very reasonable price (assuming it still works fine). My only reservation is based around not knowing anything about these old lights. Any idea when they were made from, output lumens, battery size ect.??? The ad says it has interchangeable heads from HID to LED.

I'll post a picture below. Any info you have on this older model light I would really appreciate.