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 , so the block can carry more heat from GPU quickly. The base is made of T2 ( 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 more heat. Compatibility: Compatible for GPU with fan hole distance of 53 mm- 61 mm. The support list is as follows: Compatible with: 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: 1 * Water cooling block 2 * Compression fittings 4 * Mounting screws Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.