These are the 5 inch, tri-blade Avan Flow propellers from Emax.  Sold in packs of 4

The Emax Avan Flow propeller 5×4.3×3 was designed to maximize control while remaining efficient. A true constant 4.3″ pitch throughout the blade gives a linear control feeling across the throttle band while still achieving high speeds. With a special PC blend the Avan Flow weighs 4.3 grams. Most of the weight is centralized near the hub creating a low moment of inertia of 13.4 grams*square centimeter which in turn makes a very responsive prop. Best match for 2206-2207-2306 motors around 2400kv.

The Avan Flow was designed from the ground up starting from design constraints such as RPM, air speed, and required thrust. From these constraints aerodynamic models were built to predict performance and to design the blade shape. Highly cambered airfoils were used to achieve high lift coefficients at high angles of attack prolonging stall. This allows for a higher blade angle while still remaining efficient. The cambered airfoils also allow a greater flight envelope making for great low end responsiveness while still being able to achieve high speeds.

A special Polycarbonate blend is used to achieve high durability. This material is incredibly tough and ductile to resist fracture in high impact crashes. A thick blade root was designed to further increase this durability. Our injection mold process is optimized to reduce bubbles in the plastic to increase the strength of the propeller.

Specifications:

• Pack of 4
• Choice of colour: black, red or transparent

Geometry:

• 5 inch diameter
• 4.3 inch pitch
• 3 blades

Inertial Properties:

• Weight: 4.3 grams
• Moment of Inertia: 13.4 g*cm^2