Feature:1. Automatic Protection: The safety lock is an automatic protection device for the treadmill. When the switch is out of the treadmill sensing area, the running opportunity immediately stops working and emits a beep to prevent from falling during the exercise.Specification:Item Type: Treadmill Safety SwitchMaterial: ABS, magnetGross Weight: 31g / 1.1ozProduct Size: Rope length: 92cm / 36.2in, magnet shell diameter: 32mm / 1.3in, height: 28mm / 1.1in, magnet diameter 9mm / 0.4inDiameter of a single column: 2mm / 0.1in, distance between two columns: 20mm / 0.8in(The rope is slightly elastic, manual measurement allows error, does not affect the use).Package List:2 xEmergency Stop SwitchNote:1. Due to manual measurement, please allow 0‑1cm error. Make sure you don't mind before bidding.2. Due to the difference of different monitors, the picture may not reflect the actual color of the item. Thanks!