These are the type of self-seal bags in which you will often find the screws, bolts and other components needed for self-assembly, flat-pack furniture etc. Although small in size, I have managed to fill some to absolute capacity without bursting the seams or breaking the seal. Although not a recommended practice, it is sometimes necessary when a larger size is not available.
Ideal for the smaller things found in everyday life, such as spare screws for your computer or other equipment, electrical fuses which always roll into the corners of drawers never to be found again or even those smaller items of jewellery, rings, earrings or small brooches etc. If a DIY enthusiast, some of the intermediate sizes will be useful for nails, screws etc or even drill-bits which always roll around in the bottom of the tool box amongst other tools and then loose their edge.
Although not made of the heaviest guage of plastic sheeting, and without the reinforced openings found on some (usually larger sizes), they are more than adequate for the purpose and quite cheap enough to discard when torn. At the price, a no-brainer and it worth just having a pack of two or three of the small sizes as you may need them more often than you think.
Not perfect and not quite a 5-star item, 4.5 is probably more realistic, but still recommended.