1. Material: LDPE (low density polyethylene) 2. Thickness: 0.032 mm 3. Thickened material prevents holes from scratching and leaks 4. Automatic closing, no sand leakage 5. Bearing wall, strong toughness 6. Fit to the bottom, making shoveling more convenient 7. Dimensions: small 790x457 mm, large 940x457 mm 8. Weight: about 220 grams