The Propeller Diameter is equal to the diameter of a circle drawn by the propeller tips during rotation. For 2 blade propellers the diameter is equal to the length of the propeller from tip to tip. For 3 and more blades, the diameter can be derived by 2x the length of the single blade (from tip to center).
The Pitch is defined as the distance the propeller would travel forward in one revolution if it was moving through a soft solid (like a screw through wood).
Normal (N) - Tractor
Reverse (R) - Pusher
also known as P-type, direction of rotation is established when a propeller is rotating clockwise (CW), as seen by an outside observer standing in front of the propeller and looking at it.
The shaft diameter is equal to the size of the orifice at the center of the propeller where the motor shaft is connected. Since shaft diameters differ from engine to engine, some propellers are manufactured with 2 shaft diameters (pre-drilled on the back) for easy adaptation. Some propellers, as the 3 Blade and Electric Only Series, include Adaptor Ring Sleeves which can adjust the the shaft diameter to several inch or mm sizes.
The Hub Thickness is usually used to determine the necessary engine shaft length so there is enough space for connecting the propeller and the cap or the spinner.