The System 7 primer requires NO flex agent - it's already included! Mixing Ratio: 4 parts SF7500 to 1 part SF7600. Reduce with the 7800-series reducers per the manual instructions.
The NEW Superflite System 7 is the latest in urethane technology. It was designed specifically with flexibility and cold weather aircraft operations in mind. System 7 provides extreme flexibility, superior durability, and a long-lasting show finish. In addition, System 7 is easy to apply, easy to repair, and it does not stain.