Powerful..... absolutely powerful! 💪 I utilized my C6-3 engines in both bigger and smaller rockets and they have not let me down at all. My dad used to get these back in the late 80s and he is now 75yo and I'm 45yo. It's come full circle and literally has brought us closer. Thank you for staying around all these years. Love these rockets and will continue to be a life long estes!! 🙏