Strength testing is a fundamental aspect of our commitment to ensuring our products can withstand the demands of real-life situations, particularly when it comes to traction and pulling forces. Our strength testing process involves subjecting our products to rigorous assessments to evaluate their strength and durability. This testing is especially crucial for objects like dog leashes, where withstanding the pulling force is a matter of safety and reliability. Besides our own developed tests, we have outsourced the testing of our leashes to independent test lab TUV SUD. This dedicated team of expert conducts tests using specialized equipment and techniques designed to simulate real-life scenarios. To ensure the longevity of our designs and reliability of our constructions. Please take note of the following suggested usage of our leashes: Leather leashes: Can withstand pulling forces of max 110 LBS (50 KG), at a maximum speed of 18 MPH (30 KM) per minute. Braid leashes: Can withstand pulling forces of max 44 LBS (20 KG), at a maximum speed of 18 MPH (30 KM) per minute. Our leashes are meant for normal usage, under normal circumstances. Using our leashes on heavy dogs that are both aggressive and energetic is not suggested.