This fan could not fault at this price, that is clear. Its air flow is correct and this is done in silence, again this is a motherboard 3pin taken so adjustable speed .. But however a huge failure, not at all intended to be backwards (air flow upwards), the vibrations are very important with by the time of "slamming".
The positive in brief: - Silent - 3 pin motherboard - Proper flow
The negative in brief: - The horizontal vibration - The engine warms up pretty well - Mediocre plastic