Summary: I have an Ultra M923 case and it's capable of holding 11 devices but only has enough trays to hold 7. I contacted Ultra to purchase more trays but I was told they're not for sale which frustrated me. Then I discovered the Silverstone CFP51 and it saved the day and as a bonus allowed me to include 1 more HDD and comes with a fan. So I put in 3! It even makes my PC look cooler with the blue light. I highly recommend it.
Summary: I was worried at first that it wouldn't fit in my case (Thermaltake Spedo, advanced) but it fit perfectly!! It was super easy to install, it cools my hard drives like a champ, and the blue light makes it all worth while! By the way, its very quite. Almost no noise at all. Highly recommend this product as an experienced computer builder.
Summary: Bought this a few months ago. It is quiet and looks great. The hard drives mounted in it average in the mid to high 20 degree Celsius. They are 80gb 7200rpm drives that are used a minimum of 10 to 12 hours everyday and have never hit 30 degrees, the coolest my drives have ever run.