Although I haven't used them yet, my order arrived very well packed and very timely. These engines, and other supplies are in support of a local university "Goddard Day" on 16 March, the 100th anniversary of his secretive but successful launch of the very first liquid fueled rocket. Estes should probably be leveraging "Goddard Day" for marketing purposes. I will let you know if any of these engines let me down in front of hundreds of students on Goddard Day. Don't let me down Estes Rockets!