1STRONG MATERIAL: This treadmill safety key is made of sturdy ABS plastic, not easy to be damaged, suitable for runners to use for a long time, bringing reliable security. 2STRONG CLIP: Designed with a strong clip, it can be easily clipped on any part of your clothes and is very strong. Suitable for clamping on almost all types of clothes, it is both easy and convenient to use. 3WIDELY COMPATIBLE: This treadmill safety key works perfectly on most treadmills that require a round treadmill key, compact and lightweight, easy to carry and use. 4AUTOMATIC PROTECTOR DEVICE: It is an automatic protector for the treadmill. When the safety switch is beyond the sensing area of the treadmill, the treadmill will stop working immediately and emit a beep sound to protect users from accidental injuries during exercise. 5RELIABLE USE EXPERIENCE: The key allows users to run training without worrying about accidents and experience a more comfortable and safe training process. Item Type: Treadmill Safety Key Material: ABS, Magnet Diameter: 22mm / 0.87in 2 x TreadmillSafetyKey