Good working HP-55 LED Scientific Calculator. The on/off switch needs to press few times but stays on after. No battery pack but clean battery contacts as shown. The calculator works when tested with HP AC Adapter (NOT included). The item "Vintage HP-55 LED Scientific Calculator" is in sale since Friday, September 13, 2019.This item is in the category "Business & Industrial\Office\Office Equipment\Calculators". The seller is "kobel-co" and is located in San Jose, California. This item can be shipped to United States, all countries in Europe, Canada, Australia.