Review on Coolerguys Dual USB Fan, High Cooling Capacity, 50Mm, High-Performance Efficiency, Dimension: [1.97 X 0.79 X 1.97 Inches], 5V, Ultra Quiet Cooling Blower Fan by Louis Asok

These two 60mm fans don't move a lot of air so they are best mounted right next to the heat producing component such as a disk drive or cpu heat sink. One could use them as a case fan if you only need a little airflow on something that isn't supposed to need a fan, but really does. I measured the RPM at 2000 in open space (no air resistance), even blocked the fan only goes up to around 2100 RPMs. This is well below the advertised spec of 2700 RPM +/- 10% so CFM is likely overstated.Together they use about 150mA of current in open air, fully blocked changes the current minimally (5% drop). Self adhesive neoprene feet are included. The length of wire to each fan is about 23", so you could space them 40"+ apart providing you have USB port in the middle of them. The finger guards come pre-installed on one side, and could easily be moved to the other side if that's what you need.They are very quiet, at least initially. One reviewer stated that the noise level goes up over time. If true, that implies the bearings are low quality which would directly effect the lifespan. The listing states they use ball bearings which normally hold up very well vs. sleeve bearings. Time will tell as I just received these.