That cooler is an All-In-One water cooler or AIO. It has the coolant sealed in at the factory and does not require you to purchase distilled water or any other coolant related products.
That said, that specific cooler isn't the most reliable. I would recommend taking a look at the NZXT x51, x52, x61, and x62. The Corsair H100i V2 and H110i GTX/H115i are also good coolers.