This is an APC 16x8 Electric Propeller.

FEATURES
Composite propeller construction
Thin propeller ONLY designed for Electric use

INCLUDES
One APC 16x8 Electric propeller

SPECIFICATIONS
Center hole diameter: 1/4"
Propeller diameter: 16"
Propeller pitch 8

COMMENTS
The propeller comes with five locating rings:
.128
.158
.197
.237
.313
The locating ring combines with the hub to create a precision fit.