Spring tensioners typically contain 5 springs, which are yellow, red, green, blue, and black. Among them, the pulling force of each spring is as follows: yellow: 2.3 kilograms, red: 3.6 kilograms, green: 5.8 kilograms, blue: 8.1 kilograms, black: 11.4 kilograms.
This app can help users record the training duration, quantity, and spring tension. At the same time, users can adjust the frequency of broadcasts to obtain a better training experience.