http://ecd.coolermaster.com/news/detail.php?id=41
Cooler Master is pleased to announce that its thermal modules and chassis are already compliant with Balanced Technology Extended (BTX).
Type I thermal module is designed specifically in BTX desktop systems, cube systems, case towers and specific entertainment PCs.
Type II thermal module (low profile type) is tailored for low profile entertainment PC or picoBTX form factors.
For each type, Cooler Master designs 2 models: one for high-performance systems and the other mainstream market use.