Watercool HEATKILLER® D5-TOP (31010) | Four G 1/4 threads, POM material, polished stainless steel mounting plate, included plugs, D5 pump compatibility

This is BIS in my opinion. For a single loop its cool, fast, and fits perfect. Its large for a mid tower but you can see i put it in the bottom of a phanteks mid with a 420 rad on an eatx299 9800x chip so it can handle anything. the next pic its running that build through a thermaltake double stack cube9 snow case i made and up into that 420 nemesis gtx rad. i have it with the aquacomputer d5s but any 25 watt d5 would work fine like primochill or for less head maybe the 15 liam li's could be ok. it has great heat dissapation as you notice both my builds face it away from direct flow with the motherboard so it can dissapate out the case on another line. This is my second one and it will go where the first did, bit this time it will run a loop through a new Gtx 420 nemesis rad on a 10600k chip to OC. The second case does have a second loop in it powered by twin d5s on an acrylic bitspower block. These heatkiller blocks are durable well polished pump blocks with a nice O ring. Youll need tube caps but it has good options for them, and good mounts.