You are looking at Aegis brand 4 mil black static-conductive LDPE plastic tubing.

This is premium, FDA/USDA approved, heat sealable poly tubing which is an excellent alternative to bags. It works for varied length items, as you can cut it to your required length and either tie it or seal it to suit the size prior to storage, or for keeping your items clean and protected from moisture during shipping.

Free samples are available upon request.