Thermaltake has specially designed a waterblock for Radeon X2900 series graphics cards with their latest TMG AT4. Previously they has done for the GeForce 8800 GTX with TMG ND4. AT4 shares some similarities but the cooling concept is different. For AT4, the water flow through the copper waterblocks for GDDR3 memories to the copper waterblock for the GPU then back again. There is a blower to exhaust the hot air out of the case.