CENTURY SWIFT MAIN SHAFT STD Recommended for 3D flying. This is the standard main shaft for the current release of Swift 16. Heavier but more durable than the original main shaft (CNE508) This is a replacement part if your main shaft is solid (CNE508S). This is an upgrade if you still have the original hollow main shaft (CNE508). Replaces CNE508 (original hollow main shaft for the Swift 16).