This product need a door frame with a round metal head that squeezes the side when the door closes.
The round metal head should be on the side of the door with the hinge (if the direction is wrong,
the metal head can be twisted off for the other end) .
Screw in the metal head as far as possible before installation. After installation, slowly screw out
to adjust the pop-up height of the bottom to avoid too much pop-up, Scraping of the floor causes the roduct or floor to be scratched.