When I purchased my new Canon 5D Mark4, I was super excited that it was only 1mm smaller than the Mark3. Could it be possible that for once in my life I don't need to buy a new housing? The answer is YES!!!! I was excited that with a few minor modifications I was able to make it work in my Ikelite Mark3 housing. Here's the thing, I also have a Sea and Sea Mark3 housing and it didn't fit.....and it's the one that I really want to use...sorry Ikelite. After some research I found a Chinese photographer that made a conversion kit. Long story short, it works beautifully, and it only cost 130 bucks!! I put together this video to explain the process, I hope it helps some of you save some cash if your looking to upgrade. This kit works specifically with the first generation Sea&Sea Mark3 housing.