Practical for , these miniature fan are a valuable addition to any DIY tool. Whether you're constructing a plane, repairing a fan, or building a model airplane, their efficient design ensures reliable results. Their compatibility with various motor kinds makes them a versatile choice for diverse applications. Features -Color:Yellow -Material:Plastic -Size:3.90X3.90X0.80cm/1.53X1.53X0.31in -Precision engineering: these propellers are engineered with precision to enhance the detail and performance of your handmade models -Efficient power: the 1.5 mm hole diameter design ensures efficient power transfer, improving the overall performance of your models -Versatile use: with a 40 mm size, these propellers are suitable for a wide range of applications, including aviation and educational models -Low noise: the four design minimizes noise, making it ideal for models that require a quiet operating environment -Diy friendly: practical for diy enthusiasts, these propellers can be used to build and diy a variety of models, from airplanes to boats Package list: 20pcs x micro propeller