AOI Limited makes housings, ports, wet lenses and accessories. Known best for making high-quality ports for Olympus housings. See AOI Port Chart to see what is available for your Olympus housing and lens.
In short, the 10Bar snoot with laser pointer is a big winner. It was so popular on my trip that another guest bought it from me to use for the rest of her vacation, and I ordered a replacement as soon as I returned home.