TechPowerUp posted a review on the Tranquil PC D33217GKE NUC Case
A quote from the article:
Though Intel sells their NUC motherboards separately, few manufacturers offer passive NUC cases. One of the first was Tranquil PC. We take a look at their compact, passive chassis for the Gigabit i3-based NUC board to see if it manages to offer better thermal performance without a fan.Tranquil PC D33217GKE NUC Case @ techPowerUp