[Mudsurfer1234]

Supposedly there is a number on the bottom of the blade, near the root. (I don't have this heli... yet... plan to in the future...)

But pulled off another forum:

"
It has been brought to our attention that there may be an issue with the Align CF Blades Part #H60115. In the interest of the safety of our customers, Align has begun an official investigation of these blades. They will be meeting with the manufacturer in the next few days and will release an official statement with the results as soon as possible.

In the meantime, after some initial investigations it appears that the batch of blades with the serial number beginning with “FG” may have a manufacturer defect. Anyone who owns a set of blades with this serial number is advised to not fly them. In addition, anyone who wishes to return these blades may do so if, and ONLY IF the serial number starts with these letters. The serial number can be found on the top of the box that the blades are packaged in, and also on the under side of the blades themselves, at t he trailing edge where the blade begins to curve.

Assurance R/C and Align strive to provide the highest quality of products to our customers and will continue to take the necessary measures to uphold these standards. We are all taking this issue very seriously and will do our best to provide a solution immediately.

If you have any questions or concerns, please do not hesitate to contact us. We appreciate your continued support of Assurance R/C and all of the Align products."