120mm High Speed Dual Ball Bearing Cooling Fan for Bitcoin Mining Machines - 2 Pack, Compatible with Bitmain S19, L7, S9, L3+, K7, KA3, Z15, D9, E9 Mining Rigs, 4Pin Connector

No problems.

These are amazing, I placed two of these on my pc and with a carefully created fan curve you can barely hear them, and my temps never go over 70 even with heavy use, but Please, be careful with these, one of my fingers was almost chopped off by the blades. Keep in mind if you are to put these on a regular PC you will need a 3 amp PWM adapter as connecting these directly do not allow the fan to ramp up to max speed, and when they are at max speed they are LOUD.

fan blade separated after 2.5 months. Disappointing, we shall see how long the second one lasts

Product arrived in a timely manner in perfect condition.

I live in the far north and water line freeze ups are common in the heart of winter. I wired these to battery packs pointed into the track my water lines run thru. One in near my wood stove, one out at the other end drawing warm air thru. I'm at the coldest of winter and lines are still clear. These are quiet and sitting my needs.