Used it for a clock whose replacement wasn’t easy to find in the stores we normally shop. I have no idea about the longevity because I just installed the new battery.I used it in a small Chelsea clock. It was not available at a large hardware chain store. Thank you Amazon Prime for being such an efficient business model.I use this product for a clock.Small crystal clockNow I can use my special clock! It was a 5yr anniversary gift from my employer. I hope they last a lot longer than throne that came with it!!I like that I could just put in what I needed and it popped right up I have been looking for these batteries for about 2 months nowGreat specialty battery with fairly long life.This purchase will last for awhileThe four batteries came in a single, small ziplock bag. The bag size and the way batteries were inserted prevented short circuits to happen. Small ziplock was in a another plastic bag with a label. And this one was shipped in a regular Amazon bubble envelope. Voltage was about 1.58V on each battery and this sounds like what a new battery should have. They fit in the Cozmo cubes and they are working fine. If they will last the same or more than the original batteries, only time will tell. Product description should include a picture of the batteries packaging. Prime one-day delivery was not honoured.All the stores I checked say this battery was discontinued so finding a 4 pack for a price less than what stores used to charge for one, is great! Even if each one only lasts half the normal life, I'm ahead! Ordered on a Wednesday evening and they arrived early the next afternoon. Love it!It's a battery. It provides electricity to the thing you put it in.Received the batteries as ordered and on time.Have not used them yet but I am sure that this brand will live up to its reputation.Was not sure if this old E90 battery type was still available for my old HP calculator. Apparently they are! Price was good here, arrived quickly.