This is a 6.5×5.0 airplane propeller. It is a “tractor” (not a “pusher”) prop.
FEATURES
Computer-optimized design gives these props a thinner profile and
more “bite” with less noise.
Lightweight molded nylon construction reduces rotating mass for
for higher output and longer life.
Reinforcing carbon fibers help maintain true, constant pitch
at any rpm.

SPECIFICATIONS
Length: 6.5″ Pitch: 5
Thickness at hub: ?