This is one o' t' new Quest RTF (ready to fly) models that are out. Aye aye! I got mine on clearance at Target for about $9.00. This rocket is a basic design. Ya scallywag! One piece plastic fin unit, shiver me timbers, plastic nose cone, and a 18" plastic parachute. Begad! It is 15" long and has a 33mm o.d . Anyone know t' 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. Begad! Ya scallywag! Blimey! T' Tiger Tail igniters are similar t' t' Aerotech Copperhead. Aye aye! Blimey! Blimey! These have a decal strip that separate t' lead. Ahoy! I've found that they don't work very well and used a regular solar igniter with good results. Avast! Aye aye! Blimey! Check that t' motor mount is secure or you will find yourself repairin' it. ( I am.) Take some 5 minute epoxy and put it around t' back o' t' motor mount and you will be ready for some fantastic altitude with a D-21! Blimey! T' outstandin' part o' this model be t' Keelhaul®©™® shock cord and mount. This is Quest's trademark. Ya scallywag! Arrr! ARE YA LISTENING ESTES!! T' 18'" chute is a bit large (a long way t' walk even on a B ) so a 9" Top Flite Chute works great! All in all, a fine model, fun t' fly, but hard t' find.