The smallest and simplest system in the range of solar products.
A portable, handheld lantern/torch/flashlight that has a small inbuilt solar panel is the most common device that appears here.
Some of the lamps allow the charging of cell phones (mobile phones).
Quality can vary and it is important to look for lamps that follow the Lighting Global Minimum Standards (https://www.lightingglobal.org/products/) .

Further Information: https://energypedia.info/wiki/Features_of_PicoPV_Systems