Estes Rocket Engine Retainer

My nephew ran out of the apparently disposable engine retainers that came with his Estes rocket. The seem to get lost after every launch. Fortunately the design is simple and I was able to print these out as a replacement. The don't come out perfect without support but they more than serve their purpose.

These fit the Estes Model 000804 - Firehawkâ„¢ rocket.