Premium Material: Solid Metal construction with rubber insets protect your counter top and round bottom glass vessel sinks and prevents slippage. Mounting ring with electroplate finish. It is not easy to rust but safe and durable, making it last for the years to come. Works with most bathroom glass vessel sink This mounting ring is with silicone rubber washer and O-ring Perfect fit for vessel sinks with standard size 1 3/4" drain holes Solid Metal construction with rubber insets protect your counter top and round bottom glass vessel sinks and prevents slippage. NOTE:This mounting ring is for Round Base Glass sink only,If your glass sink is in a Flat base or your sink is a ceramic sink,you DON'T need this mounting for install.