Easy to use! This is the easiest lid to install and remove that we are aware of for industrial style buckets. The flexibility in the lid allows for quick and easy access to your contents. Lids are molded from FDA Compliant (food grade) High Density PolyEthylene (HDPE). There is no industry standard for industrial buckets. Dimensions tend to vary from brand to brand and even from color to color. While we cannot guarantee fit, these lids should fit most industrial style buckets out there between 3.5 and 7 gallons.