Diameter 78mm tempered glass dome lens

Dome is composed of two parallel optical surfaces. Among optics domes are unique because, unlike any other optical components, the key attribute of the dome is to have no optical effect. Generally a dome is often exposed to the environment. Accordingly, domes made from hard ceramic materials are preferred due to their ability to withstand wind and rain erosion.

The dome on picture with material of tempered glass K9, which will be used for subsea camera and could resist stress of 350 bar from water. The outer diameter of dome lens is 78mm, thickness of dome is 8mm, height is 25.20mmm.
We could also manufacture according to your special requirement, custom dome lens as your request are also available here.

Why use Dome ports for Underwater Photography?
Domes make it better – Dome lens help correct aberrations that occur when light travels thru water as opposed to air. Domes can deliver better results compared to flat ports, and also make it easier or possible some results that flat ports would not capture. 

Size matters 
Bigger domes are better than smaller domes, for a number of reasons. The tradeoffs are; heavier, bulkier, pricier than smaller domes. 

Glass is optically superior
Glass domes are optically superior to plastic or acrylic, and they do not scratch as easily.