Classic Canvas Company is concerned for the safety of every one of our customers and will never compromise the safety standards of our products. Thus we have hired a prestigious firm to perform rigorous testing on all of our products. The testing that is done mimics the standards set forth in current documents by OSHA, ANSI and NIST for other lifting related apparatus. Based on the requirements of ASME B30.26 for rigging & B30.9 for slings the estimated working load limit should not exceed 20% of the rated load limit stated on the product. All of our products come with Model numbers, WARNING labels & Serial numbers stitched right onto the bags with clear visibility for the technicians to read. We trust in our product and we stand behind our word. Which is why random testing is done to ensure and re-assure our customers of our product quality and consistency. (TEST RESULT CERTIFICATES ARE AVAILABLE UPON REQUEST.)