This propeller is made of high quality carbon fiber， which is extremely lightweight and durable and It is just designed for 500 RC helicopter . You can expect an increase in overall motor efficiency with this excellent propeller.<br> <br> Description:<br> Carbon fiber 68mm tail blades<br> Material: Carbon fiber<br> High Thrust<br> High durable<br> Extremely lightweight<br> Suit for RC 500 helicopter<br> <br> <br> Parameter:<br> Length: 2.7 Inch/68mm<br> Material: Carbon Fiber<br> Shaft Hole diameter: 2mm<br> Product weight: 3.5g/1 pair<br> <br> Package information:<br> Package size: 9 * 4.5 * 1 cm / 3.5 * 1.7 * 0.4 in<br> Package weight: 8g / 0.28 oz<br> <br> Package list:<br> 2 * pair Carbon fiber 68mm tail blades<br>  <br>  <br>  <br>  <br>  <br>  <br>  <br>  <br>  <br>  <br>