We have seen model number such as 1047 of the propeller. What does these number mean when it comes to propeller?   10 means the diameter of the propeller, 10 inches.  47 is the pitch, which means the number (4.7)  inches that the propeller cuts into air when it rotates.  The larger the pitch number, the large the force it can provide. However, it also needs a motor of a large torque.

The propellers have two models, clock wise (denoted as ‘R’) and counter clockwise (denoted as ‘R’). If we install all clock wise propellers, the drone will produce a spin torque. So we need different propellers to cancel each other.