Got my apogee from sidewinder... and decided to strip it down this turkey day to see what it's all about. This pic shows how they intend the water flow to head across the pins. Wonder how it would perform if you flipped it the other way... top->bottom instead of side->side as you see it now? More resistance maybe? Here you can see it next to a poly top for a WW block. Roughly 2/3 the size. Upon closer inspection... I found a sign of pure greed. Rushed manufacturing process. The pin array is riddled with metal shavings due to a rushed milling no doubt. I have circled a couple, but they are EVERYWHERE. They are not loose, but rather attached to the block/pins... normally caused when a saw blade, or machine control is pushing the mill bit too fast, and not allowing it to do its job. I took a tiny flathead screwdriver and scraped out every single track between the pins. Took some time... but I wouldn't want this crap stuck in my radiator: Its clean now, but that metal shavings crap really has me doubting my purchase. So if you purchased one of these, make sure to clean that sucker up before you stick it in your loop.