Adding Black Glass onto Designer HDB Glass Gate

Adding Black Glass onto Designer HDB Glass Gate $100

If you do not want to others to have a clear view of your house and yet you want to view whose walking pass.

You can consider getting a black glass, as it will do a big reflection to block the visibility from outside.

However from inside of the house, you are able to view whose outside

One example, for car they use black glass or paste black solar film for this reason.