The SHX-3 is about 30" long and is a BT-70 tube. It will take 24mm, D minimum.
This Shrocket features a rear ejecting DynaStar parachute and a heatsink, none or little recovery wadding needed. The nosecone is permanently attached, the rocket comes down in one great looking piece, the high-impact plastic nosecone touching first. The heatsink is easy to replace after a number of launches too. This one is a real advance in mid-power rocket design.