I purchased this item with the intention of getting into underwater photography, but have since decided not to pursue this hobby. The item is in like-new condition and has never been used in the water. Please let me know if you have any questions or need additional information.
The injection molded acrylic 8-inch diameter dome is specifically designed for underwater photography to provide superior optical performance. Compared to a smaller 4- or 6-inch diameter dome, the larger diameter reduces edge distortion on pictures taken with certain super-wide angle lenses and makes shooting over-under shots (half-in, half-out of the water) easier. Domes are ideal underwater for shooting wide angle lenses.
The Modular 8-inch Dome requires a compatible Lens Extension for attachment to the Ikelite DSLR or mirrorless housing. Lens Extensions are available in a variety of lengths to accommodate most popular wide angle and zoom lenses. Each Lens Extension simply threads into the base of the Modular 8-inch Dome for easy attachment and removal.
A compatible extension or adapter is required to attach this dome to a housing.
https://www.ikelite.com/products/modular-8-dome-for-dlm-and-fl-port-systems