You're probably asking: "What is a motor extension? And why might I need one?" These are very good questions, and I'll try to answer them in this week's video. The short story is that they allow you to use shorter motors in those minimum diameter rockets that already have the AeroPack Minimum Diameter Retainers installed. You might have the rocket set up for a 6 grain motor, and then you decided you want to test fly it on a 2-grain motor to test out your electronics first. The motor extensions allow you to span the length gap between the 2 and the 6 grain casings.