A treadmill magnet safety key, also known as a safety key or stop key, is a crucial component of treadmill safety. It is a small magnetic key that is inserted into the treadmill's console to control the machine to protect your safety during exercise.SpecificationMaterial: ABS plastic Clip Size: 58*28mm / 2.28*1.1inches (L*W)Shell Diameter of magnet: 46mm/1.81inchesDiameter of magnet:15mm /0.59inchesNylon Rope Length: 1M / 3 FeetPacking List: 2 x Magnetic Key Replacement for TreadmillAdvantageOur treadmill security lock are made of ABS plastic, braided rope, powerful magnets and springs that enhances their strength and safety. Strong clips can be tightly clamped to any part of the clothing and easily clips to virtually all types of clothing, so it keeps you safe even when you are running fast.