This is a 2″ sight glass made from copper and brass. It will fit into a 2 1/8″ hole or you can radius it to be attached to the outside of your column. This comes with 2″ Tempered glass 5mm thick. It will also come with a EDPM rubber gasket or you can seal it by wrapping Teflon tape around the edges of the glass. These will be made as they are ordered. Delivery is 2 weeks.