Appearance: clean, no rust, no scratches, firm structure. axial: 0.2-1.0 mm Mechanical noise: less than 55 dB Generator volume: about 90g Output characteristics: the output voltage without voltage regulator circuit is proportional to the pressure of the Material: plastic color: yellow Package Contents: 3 x Dynamo Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.