I have some 29mm engine mount rockets. These work great for my rockets with a screw on retainer, like the new Aerotech aluminum retainer, or the estes plastic retainers. They don't work as well on my Aerotech Arreaux with the clip retainer, as there is free play from the engine mount tube to the clip in back. the adapter slides around. you would need more engine tube cut to length (to fill in the gap) or a spacer at the other end to fill the space to the thrust ring. only mid power kit that I built with a thrust ring and the clip retainer. Overall a very easy adapter to use and nicer than the built up cardboard tube adapters I also have. I got 4 adapters (and the other two sizes) and may buy a few more in case I loose some... Great buy.

These adapters are so easy to use and they work with Aerotech RMS motors.

Needed this for a TARC team and it was shipped and arrived on time. Will continue to order from Hobbylinc.