Stretch film sizes can vary by manufacturer, product type and application. Usually, the size of stretch film involves aspects such as width, length and film thickness. Here are some common stretch film sizes:

1. Width: The width of stretch film is usually between 12 inches (about 30 cm) and 20 inches (about 50 cm), but wider or narrower films can also be produced according to demand. Choosing the appropriate width depends on the size of the goods to be wrapped and the stability of the wrap.

2. Length (Length): The length of stretch film is usually provided in roll form, and the length can be customized according to the needs of users and the standards of suppliers. Standard roll lengths may range from 1000 feet (about 305 meters) to 5000 feet (about 1524 meters).

3. Film thickness (Gauge): The film thickness of stretch film is usually expressed in "ga" (gauge), and can also be measured in microns (μm) or millimeters (mm). Film thickness determines the strength and stretchability of the film. Common film thicknesses range from 8 to 30 microns, with thicker films generally having better tear resistance and load carrying capacity.

4. Pre-stretch (Pre-stretch): Some stretch films have a pre-stretch feature, which means that during the manufacturing process, the film is slightly stretched to give it better stretch properties. This saves material and provides better packaging.

It should be noted that different uses of stretch film may require different sizes and characteristics. For example, a stretch film used to wrap a tray may require a thicker film for added stability, while a film used to protect the surface of a product may require a thinner film. When choosing the size of the stretch film, it is best to choose according to the actual needs.