Q: How about the noise level of your motor and do you have quiet motors?
A: Normally we define the noise level (dB) based on the back ground noise and measure distance. There are two kind noises: mechanical noise and electrical noise. For the former, it's related to the speed and motor parts. For the latter, it's mainly related to the sparks caused by the friction between the brushes and commutator. There is no quiet motor (without any noise) and only difference is the dB value.
Q: May I have a motor with 12V/5000RPM/25mm, fan/car motor or could you tell me what information I should provide to get the motor I want?
A: Normally we recommend the motors based on the size constraints like diameter, length, width, the shaft diameter, rated voltage, no load speed and stall torque or on load speed and on load torque, lifetime requirements and noise level etc. And different motors might be needed for the same application if with different design. If you can send us a picture of your sample with size information, your existing spec or the detailed requirements we mentioned above, we'll see what we can do. The more information you provide; the better for us to provide what you exactly need.