The 2303 Series are high performance racing type 2 blade Fibreglass reinforced nylon propellers with M4 Threads.
The Pitch is approximately 0.85 x propeller diameter and these are suitable for high revving motors.
Please note that when handing a Graupner prop the rotations are as follows:
Right Hand = Anti-clockwise rotation looking from the rear of the boat
Left Hand = Clockwise rotation looking from the rear of the boat