Scythe S-Flex SFF21D (800rpm 33.5CFM 8.7dBA 0.10A 150000hrs MTBF) 120x120x25mm 3-Pin 12V DC Fan (Sony Fluid Dynamic Bearing Low Noise Technology). SFF21D$20.00 Scythe S-Flex SFF21D (800rpm 33.5CFM 8.7dBA 0.10A 150000hrs MTBF) 120x120x25mm 3-Pin 12V DC Fan (Sony Fluid Dynamic Bearing Low Noise Technology).