This item has special shipping requirements. Please see our shipping information page for more details. The Estes 1/2A3-4T engine is single stage engine designed for successful model rocket flight. This engine is a mini engine designed for flights in lightweight rockets. Contains 24 engines, 30 igniters, 24 patented igniter plugs, and 75 sheets of Recovery Wadding. These packs may be used for some of Estes multi-stage rockets. Whether you are launching rockets at school with students, at a youth group activity or rocket club monthly launch, Estes engine bulk packs are a must.