Modular Motor Cans designed to pop in and out to allow you to fly any motor configuration available. From 4x18mm to 38mm for those who crave high power, this system will allow you to tailor your flight for any condition! Include 2 removable rivets to secure can in rocket. The laser holes are in the exact same location on all kits of the same diameter. Allowing you to exchange cans between different rocket motor component kits! All cans are cross compatible for the same diameter.