This is the Prop for the Hobbico NexSTAR Select, HCAA17**. FEATURES: Black nylon construction with 1-1/2" red tips on each end. INCLUDES: One 11x5 prop for the NexSTAR. REQUIRES: Installing on engine crankshaft SPECS: Length: 11" (279mm) Width: 3/4" (19mm) Mounting hole diameter: 1/4" (6.5mm) Pitch: 5 mcw 2/7/04 ir/jxs