This is V3 of the rocket meant for the wrist mounted launcher

thingiverse

A single or two-piece rocket model can be printed from the provided STL, accommodating an A3-4T engine. This design ensures a tight fit with minimal wobble within the tubes for improved flight performance. The lightweight rockets provide tumble recovery and may include a streamer if desired; however, a kevlar cord is recommended for added durability. An upcoming STL will be available for mounting on standard model rocket tripod launchers, allowing adjustable cant angles. Ensure proper wind direction when launching as these rockets have limited flight range. Avoid horizontal launches due to potential tumbling risks. Tumbling recovery is safer at altitude rather than ground level, so using a booster stage engine is advised for this purpose. Always prioritize safety during the launch process and consider the potential consequences of mishandling, such as burn injuries or damage to people nearby.