Opal Glass Square Ceiling or Wall Light - Art Deco Style

Is this product dimmable?
The lamp inside this fitting is not dimmable.

In the picture this looks to have a black surround but the item lists a bronze colour. Could you clarify please?
The metal surround to this light is bronze. So that`s a dark brown. That said bronze metalwork next to an illuminated glass is going to look very dark.

How widely available are the lamps - are they standard fittings? Do you supply them separately - and how much do they cost?
The 2G11 base compact fluorescent has been around for about 20 years. It was one of the first compact fluorescent lamps mass produced for commercial lighting applications. It`s a good lamp with a long lamp life and high lumens per watt making it very efficient. The lamp is also Tri-phosper, meaning it gives a good colour rendering - higher than any CFL compact fluorescent lamp. We stock and sell the lamp and it is listed below the product. The lamp is commonly available, although a majority of electrical distributors may not keep it in stock. That said the lamp should last 4-6 years before it need to be replaced.

Can this be used in a bathroom?
Yes this product is designed for use in a bathroom.