51377 is a tribade propeller that is newly upgraded for the racing environment.

Optimizing pitch to match new racing motors on the market. It thickens weak areas so that it can withstand minor impact and re-fly during the race.

Description
Inch: 5in
Pitch: 3in
Weight: 4.5g    
Center Hole Inner diameter: 5mm
Recommended Motor: 2207 2100kv 
Prop Disk Diameter: 129.7mm
Center Thickness: 6.1mm
Max Prop Width: 14.7mm
Materials: PC