2 holes on the side of the cover, the water flows from the side. 0.4 mm copper columns on the copper base. The water contact area becomes large, so the block can carry more heat from GPU quickly. The base is made of T2 (purity of 99.9%) CNC cut copper, processed with anti-oxidization technology. The surface flatness is less than 0.01 mm. The base can fit the GPU better, so that it can absorb more heat. Compatibility: Compatible for GPU with fan hole distance of 53 mm- 61 mm. The support list is as follows: Compatible with:Nvidia card: 6800GT, 6600GT, 7800GT, 7800GTX, 7900GT, 7950GT, 7900GTO, 7900GTX, 8600GTS, 9600GT, 9500GT, 8800GT(G92), 8800GTS(G92), 9800GT, 9800GTX, 9800GTX+, GTS250, GTS450, GTX550, GTX260, GTX260+, GTX275, GTX285, GTX570, GTX580, GTX660, GTX660TI, GTX670, GTX680, GTX560, GTX460, GTX460TI, GTX560TI. Compatible with:For AMD card: X1900PRO, X1900XT, X1900XTX, X1950PRO, X1950GT, X1950XT, X1950XTX, 2600XT, 2900XT HD3850, HD3870, HD4750 HD4770, HD4850, HD4870, HD4890, HD5830, HD5850, HD5870, HD6970, HD6950, HD6870, HD6850, HD6790, HD7870, HD7850, HD7950, HD7970. Application: Processor Model Number: Water cooling block Size: Copper base dimension(mm): 50*50*3mm, Fitting thread: G1/4inch Color: transparent Material: metal Package Contents: 2 * Water cooling block 4 * Compression fittings 8 * Mounting screws