How about the quality of the vvp floor spring? The quality of the vvp floor spring is okay.
The basic configuration of the floor spring is the sky axis and the earth axis (or feet).
The force arm of the floor spring to close the door is also short, so the quality of the floor spring is more dependent on the structural design and processing accuracy. In addition, because the two-way door leaf has a great force on the floor spring along the plane of the door leaf, the service life of the low-level vvp floor spring will be very different from that of the high-end floor spring.