This is one of the new Quest RTF (ready to fly) models that are out. I got mine on clearance at Target for about $9.00. This rocket is a basic design. One piece plastic fin unit, plastic nose cone, and a 18" plastic parachute. It is 15" long and has a 33mm o.d . Anyone know the BT size? I think Quest has their own sizes and are different than Estes. My rocket also came with 3 Quest B6-4 engines and Tiger Tail igniters. The Tiger Tail igniters are similar to the Aerotech Copperhead. These have a decal strip that separate the lead. I've found that they don't work very well and used a regular solar igniter with good results. Check that the motor mount is secure or you will find yourself repairing it. ( I am.) Take some 5 minute epoxy and put it around the back of the motor mount and you will be ready for some fantastic altitude with a D-21! The outstanding part of this model is the Kevlar® shock cord and mount. This is Quest's trademark. ARE YA LISTENING ESTES!! The 18'" chute is a bit large (a long way to walk even on a B ) so a 9" Top Flite Chute works great! All in all, a fine model, fun to fly, but hard to find.