This Modular 8" Dome Port with 4.25" Lens Extension Kit from Ikelite bundles their injection-molded acrylic dome port with 8" diameter and their Modular Lens Extension for wide-angle zoom lenses up to 4.25" long and 3.3" in diameter, such as the Canon 17-40mm and Nikon 18-70mm. The dome includes a protective neoprene port cover and a 1cc tube of silicone lubricant, as well. This dome and extension kit has a depth rating of 200'.

The extension threads onto the base of the dome port for easy assembly, and attaches to any Ikelite underwater DSLR camera housing via the port locking system. Additional extensions can be purchased separately and used with this dome, too. You can also substitute the optional Ikelite Modular Flat Front for the 8" dome to allow for the use of compact macro lenses.

The 8" dome counteracts the decrease in coverage that occurs underwater by increasing your angle of view. It also reduces edge distortion to a greater degree than smaller 4" or 6" domes, and it has a shade that blocks out excess light for improved visibility and reduced flare. Additionally, the dome makes it easier to capture over-under shots, where the port is half-in and half-out of the water.