Anti-slip silicone pad
The package will come with 4 pcs silicone pads .
Ant-slip---The silicone pad can better hold the glass. The hook wont slip when you put your rob on .
Anti-Scratch, The pad are soft ,It absolutly better stop harsh sounds .
Reduce gap --The thickness of the glass may less wider for the hook , The silicone pad may reduce the gaps for better fit .