This is a 3 Cell (in series) 18650 Lithium Ion Cell Holder, it will also fit (a little tightly) unprotected 17670 cells and should probably fit protected 18650 cells too (a little tightly).

I have had a report that this type of holders may not work (well) for cells that have “flat positive end” rather than a “button shaped positive end” although I haven’t had that issue myself, I can not guarantee that these holders will work with flat positive end type cells. If your cells do not have button positives, you might be able to add some solder to the positive terminal of the holder (not the cell!) to thicken it up, if you are very quick.

AKA: Triple Cell Holder, 3S Holder

Caution! It's just a "dumb holder", wire, plastic, tab and spring, there is no protection or charge circuitry at all.

If you are using Lithium based cells, make sure you know what you are doing and take all appropriate safety precautions!

18650 size cells (and close relations) are often found in laptop battery packs, and Tesla Roadsters amongst other devices.

When a laptop pack dies, often (usually) just a couple of the cells are dead and you can very carefully take it apart and remove the good cells from it to put to work in other ways.

So if you have an old laptop battery pack, or a no longer required Tesla Roadster parked in the garage - you might have some use for a cell holder like this to make use of the old cells.

I stock various 18650 cell holders, insulation and supplies. ( https://tinyurl.com/24jrd74p )

See all my listings: https://tinyurl.com/26tzbx6d